Aaenriber1008

An account is given on the value of the correlation coefficient between the number of counts in a peak in a gamma-ray spectrum and the number of counts in the background, where the peak resides. It is supposed that the decomposition of the spectrum in the peak and in the background is performed by using the Least Squares method. The values of the correlation coefficient were determined empirically from measurements of gamma-ray spectra under repeatable conditions and from analyses of these spectra using four different kinds of peak-analysis software. These values were compared to the a-priori values, obtained from the Least Squares method. Tricalcium phosphate having effective atomic number Zeff = 15.785, equivalent to that of bones was studied for its thermoluminescence (TL) and photoluminescence (PL) properties. Different samples with varied concentrations of the dopant Dy3+ (0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 mol %) were synthesized by the chemical co-precipitation technique. Phase and compound confirmations were done using X-Ray Diffraction (XRD) and the phosphors' crystallite size was calculated using Scherrer's formula which was found to range between 27 nm and 49 nm. The surface morphological study was done using Field Emission-Scanning Electron Microscopy (FE-SEM). Other characterization techniques used for compound confirmation included Energy Dispersive X-Ray Spectroscopy (EDX) and Fourier Transform Infrared Spectroscopy (FTIR). Samples were further irradiated by gamma rays (emitted from Co-60) with dose varying from 10 Gy to 5 kGy in order to study their TL properties. Concentration optimization of the given phosphor was done in terms of its TL intensity and was found to be 0.5 mol %. The TL dose response of the phosphor was linear over a wide range of dose (10 Gy-3 kGy). Deconvolution was performed on the glow curve for 10 Gy dose, giving six peaks (at 127o, 153o, 185o, 218o, 313o and 335oC) suggesting the presence of six different types of traps. Other characteristics of the TL material i.e. repeatability and fading were also studied. Overall, the phosphor showed promising results for its utility in TL dosimetry. In addition to the TL, PL further confirmed the presence of dopant in the phosphor. Moreover, the dopant concentration was optimized in terms of the nanophosphor's PL intensity. The Commission International de l'Éclairage (CIE) was used to calculate chromaticity coordinates, colour rendering index and colour temperature in order to investigate the phosphor's application in white LEDs. A 4π radiation dosemeter for use in medical radiology was designed. It is based on a solid state silicon detector, a sensor wafer, a flex card, a 3D plastic holder and a spherical stainless steel filter with a distribution of holes around the detector. The detector is attached to the wafer using only low Z material. To achieve an energy and directional response which is as uniform as possible for various radiation qualities and beam directions, the filter was designed using a series of Monte Carlo calculations. The energy filter and its hole pattern were created using Additive Manufacturing (AM) in the form of metal 3D printing. The functionality of the dosemeter was designed to fulfill the quality criteria of a combined energy and angular dependence of less than 5% for the IEC beam qualities RQR and RQT in the range of 65-145 kV. This is a major improvement to the existing solutions that may need software corrections to be used for the same beam quality range. A flowing-water target was irradiated with a 140 MeV/u, 8 nA 40Ca20+ beam to test the feasibility of isotope harvesting at the upcoming Facility for Rare Isotope Beams. Among other radionuclides, 2.6(2)E-6 48Cr and 5.6(5)E-6 28 Mg nuclei were formed for every impingent 40Ca and were collected through ion exchange. Radiolysis-induced molecular hydrogen evolved from the target at an initial rate of 0.91(9) H2 molecules per 100 eV of beam energy deposited. No radiation-accelerated corrosion of the target material was observed. Radiotracer residence time distribution (RTD) methodology was used to determine the hydrodynamic parameters of the aerobic digester of an effluent treatment plant. Technicium-99m was used as a radiotracer. The concentration of radiotracer in the exit stream of the digester was determined using an on-line tracer monitoring method. Ganetespib The experimental mean residence time (MRT) of the digester was found to be 4 h, far less than the theoretical MRT calculated with respect to nominal flow parameters (volume and flow rate of material into the digester). The experimental MRT corresponds to a percentage effective volume of 11% translating into approximately 89% dead volume in the digester leading to the conclusion that the hydrodynamic performance of the aerobic digester of the effluent treatment plant was not efficient. A radioactive tracer (Tc-99m) was used to determine the flow type in the digester; an RTD Software was used to model the flow by curve fitting the experimental RTD with various non ideal flow models. It was observed from the radiotracer experiment that the perfect mixers in series with exchange model best described the flow type existing in the digester. An analytical equation is derived for the uncertainty propagation factor for a half-life determination from a least-squares fit to equidistant activity measurements performed with identical relative uncertainties. The obtained formula applies to a purely random statistical uncertainty component. It is equivalent to the solution published by Parker in Nucl. Instr. Meth. A 286, 502. A more general equation for weighted least-squares fitting is derived and presented in a compact manner. It is used as a benchmark to verify the applicability of Parker's solution to non-equidistant data with unequal uncertainties. The radiological consequences following a severe hypothetical accident at the proposed Rooppur Nuclear Power Plant in Bangladesh, have been assessed using the health physics code HotSpot 3.1, developed by Lawrence Livermore National Laboratory, USA in this study. The source term for this approach has been calculated analytically. Atmospheric dispersion characteristics have been branded using the site-specific meteorological data of 30 years, obtained from Bangladesh Meteorological Department. The TED and GD values have been calculated in the downwind distance for six individual cases along the plume centerline from the release point up to 200 km. The cases include three seasons namely Summer, Rainy and Winter with three stability classes A, B and F prevailing around the region. The highest value of TED and GD observed is for Rainy season (Stability Class F). The three TED contours have been drawn for 1.00, 0.50 and 0.05 Sv respectively which reflect dose limits for permanent relocation, emergency worker and evacuation, as established by IAEA-TECDOC-953.