Inaccuracy Determination in Mathematical Model of Labsocs Efficiency Calibration Program

The study of radioactive materials quantitative inaccuracy determination caused by semiconductor detector aging is presented in the article. The study was conducted using a p- type coaxial GC 1518 detector made of a high-purity germanium produced by Canberra Company and LabSOCS mathematical efficiency calibration program. It was discovered that during 8 years of operation the efficiency of the detector had decreased due to increase of the dead layer of the germanium crystal. Increasing the thickness of the dead layer leads to 2 effects, which influence on the efficiency decrease: the shielding effect and the effect of reducing the active volume of the germanium crystal. It is found that the shielding effect contributes at energies below 88 keV. At energies above 88 keV the inaccuracy is connected with the decrease of the germanium crystal active volume, caused by lithium thermal diffusion

Structural Modification of La[2]O[3]-TiO[2]-B Mixture After Mechanical Activation

Accelerators require development of new and more powerful installations, generating the streams of the charged particles, affecting the development of machine building industry, energy power industry and other fields of science and technology. Great attention is paid not only to the modernization of the installations, in whole, but also to their individual elements. Cathode is the most important element of the installations, generating the stream of charged particles. Using lanthanum hexaboride as a cathode material allows getting maximum efficiency of cathode assembly due to the thermodynamic and emission properties of lanthanum hexaboride. This paper studies the properties changes of lanthanum oxide mixture, titanium and boron oxides under the influence of mechanical activation to obtain the final product, based on lanthanum hexaboride and titanium diboride, corresponding to the high performance properties of the emitter. The study resulted in determination of time and frequency of mechanical activation to obtain the particles with the smallest average size of 6.3 microns for the mixture of lanthanum oxide, titanium and boron oxides powders

Error reduction in gamma-spectrometric measurements of nuclear materials enrichment

The paper provides the analysis of the uncertainty in determining the uranium samples enrichment using non-destructive methods to ensure the functioning of the nuclear materials accounting and control system. The measurements were performed by a scintillation detector based on a sodium iodide crystal and the semiconductor germanium detector. Samples containing uranium oxide of different masses were used for the measurements. Statistical analysis of the results showed that the maximum enrichment error in a scintillation detector measurement can reach 82%. The bias correction, calculated from the data obtained by the semiconductor detector, reduces the error in the determination of uranium enrichment by 47.2% in average. Thus, the use of bias correction, calculated by the statistical methods, allows the use of scintillation detectors to account and control nuclear materials

Mechanical activation influence on the morphological properties of La[2]O[3]-TiO[2]-B

The influence of mechanical activation of the powder mixture used to obtain the high-perfomance cathode for accelerating engineering with the SHS-method has been explored. The mechanically processed mixtures have been morphologically analyzed. The optimal modes of mechanical activation have been determined for the mixture

Synthesis and properties of the materials obtained by SHS mode for radiation protection

The article shows the process of protective composite materials manufacturing. Also, the analysis of experimental results concerning the composite materials protective properties is given. The advantages of SHS method are considered in comparison with traditional materials. The uniqueness of SHS obtained products based on combination of nuclear-physical properties and parameters is presented

Automation of the Monitoring System for Surface Contamination with α-Active Radionuclides

The paper presents research on radiation control at nuclear enterprises working with [alpha]-active radionuclides. The focus of the research is on the registration of 239Pu radionuclides on hands surface. The experimental results show the possibility to create a turnstile for automatic monitoring the presence of α-active radionuclides on hands. Such a device can be used with a minimum helium consumption of 66 liters per hour in a measuring chamber with an open bottom of 5.4 liters

Mathematical modeling of combustion wave propagating in SH-synthesis of functional borides used to protect from mixed ionizing radiation

This work describes the mathematical model of SHS combustion wave propagating in the system of W-B. The model is based on the heat equation. The result of modelling is a forecast of SH-synthesis temperature regime in this system what allows forecasting a phase composition and thermal stresses. The model checking was realized in the experiment in the synthesis of this system in a laboratory-scale plant including the SHS reactor. The presented model is in agreement with the experiment in a maximum synthesis temperature and the curve rate of synthesis carrying out

Mathematical modeling of combustion wave propagating in SH-synthesis of functional borides used to protect from mixed ionizing radiation

This work describes the mathematical model of SHS combustion wave propagating in the system of W-B. The model is based on the heat equation. The result of modelling is a forecast of SH-synthesis temperature regime in this system what allows forecasting a phase composition and thermal stresses. The model checking was realized in the experiment in the synthesis of this system in a laboratory-scale plant including the SHS reactor. The presented model is in agreement with the experiment in a maximum synthesis temperature and the curve rate of synthesis carrying out

Evaluation of neutron activation of intermetallic matrices for dispersive nuclear fuel obtained by SH-synthesis

The paper describes a technique for obtaining intermetallic matrix materials based on Zr-Al and Ni-Al systems for dispersive nuclear fuel. This type of fuel is planned to be used in existing and future high-temperature nuclear reactors. Physical and mathematical modelling of the process of activation of matrices by neutron radiation showed that upon reaching the value of thermal neutron fluence of the order of 2.76·1021 n·cm-2 , the activity of Zr-Al and Ni-Al matrices was 1.3·1010 and 0.2·1010 Bq/g, respectively. The analysis showed that in terms of exposure of irradiated fuel it is preferable to use a matrix based on the zirconium-aluminium system