Usually, there are several methods, e.g. experiment, interpolation experiment-based, analytic function, and Monte-Carlo simulation, to calculate the response functions in LaBr3（Ce） detectors. In logging applications...
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Usually, there are several methods, e.g. experiment, interpolation experiment-based, analytic function, and Monte-Carlo simulation, to calculate the response functions in LaBr3（Ce） detectors. In logging applications, the experiment-based methods cannot be adopted because of their limitations. Analytic function has the advantage of fast calculating speed, but it is very difficult to take into account many effects that occur in practical applications. On the contrary, Monte-Carlo simulation can deal with physical and geometric configurations very tactfully. It has a distinct advantage for calculating the functions with complex configurations in borehole. A new application of LaBr3（Ce） detector is in natural gamma-rays borehole spectrometer for uranium well logging. Calculation of response functions must consider a series of physical and geometric factors under complex logging conditions, including earth formations and its relevant parameters, different energies, material and thickness of the casings, the fluid between the two tubes, and relative position of the LaBr3（Ce） crystal to steel ingot at the front of logging tube. The present work establishes Monte-Carlo simulation models for the above-mentioned situations, and then performs calculations for main gamma-rays from natural radio-elements series. The response functions can offer experimental directions for the design of borehole detection system, and provide technique basis and basic data for spectral analysis of natural gamma-rays, and for sonrceless calibration in uranium quantitative interpretation.
The self-propagation synthesis (SHS) technology is characterized exclusively in multiple aspects, including: higher reaction rate, simplified procedure, shortened flow-process, facilitated process, lower energy consum...
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The self-propagation synthesis (SHS) technology is characterized exclusively in multiple aspects, including: higher reaction rate, simplified procedure, shortened flow-process, facilitated process, lower energy consumption and remote control. In order to evaluate the performance of the self-propagating high-temperature synthesis (SHS) to treat An 3+ - contained radioactive graphite in N2 atmosphere, in our study, with the exothermic reaction (3C + 4Al + 3TiO 2 = 2Al 2 O 3 + 3TiC + Q), we used the following raw powdery materials including graphite (C), aluminum (Al), titanium dioxide (TiO 2 ) and neodymium oxide (Nd 2 O 3 , where Nd 3+ was used to simulate An 3+ ). After a serial pretreatment including mixing, refinement and formation, a self-developed SHS reactive facility was used to prepare the simulated waste form for the An 3+ -contained radioactive graphite. Then, X-ray diffractometer(XRD) and scanning electron microscope (SEM) were used to test and analyze the morphology, phase composition and solid solubility of the prepared waste forms. According to the results, the samples with the adding Nd 2 O 3 of 0∼16 wt % could maintain the self-sustainable reaction. And in the designed reaction, the Nd 2 O 3 solid solubility was 1 wt %. The samples were mainly in pieces, with grain sized mainly in 5∼10 μm. The samples without adding Nd 2 O 3 content were composed of Al 2 O 3 , TiC, C, TiO 2 and AlN. With adding Nd 2 O 3 content of 1 wt %, the samples were composted of Al 2 O 3 , TiC, C, TiO 2 , AlN and NdAlO 3 . While in case of adding Nd 2 O 3 content of over 1 wt %, the occurrence of the Nd 2 O 3 phase was observed in the XRD patterns of the samples.
We investigate the structure of yrast bands in the transuranium nuclei ^(242)Pu and ^(244)Pu in the framework of the projected shell model,which is a fully quantum mechanical and microscopic *** is found that an appro...
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We investigate the structure of yrast bands in the transuranium nuclei ^(242)Pu and ^(244)Pu in the framework of the projected shell model,which is a fully quantum mechanical and microscopic *** is found that an appropriate modification of the standard Nilsson spin-orbital parameters in the N =6 proton shell is necessary to correctly describe the high-spin backbending phenomenon in nucleus ^(244)*** order to test whether this modification is correct,the same modified parameters are used to calculate the yrast band of its neighboring isotope ^(242)*** is found that without this modification,a backbending will occur at spin I =20,which is not supported by the experimental data.
Behaviors and properties of helium in titanium were explored by molecular dynamics(MD) simulation in this *** influence of He number,vacancy number and He density(ratio of helium to vacancy) on the thermal stability o...
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Behaviors and properties of helium in titanium were explored by molecular dynamics(MD) simulation in this *** influence of He number,vacancy number and He density(ratio of helium to vacancy) on the thermal stability of HenVm clusters(where n and m denote the number of He atoms and vacancies) were ***,interactions among He atoms,SIA atoms and vacancies were *** results demonstrate that the binding energies of an interstitial helium atom primarily depend on He and vacancy numbers rather than the helium-to-vacancy ratio(n/m).It is different from the previous report of other *** binding energies of an isolated vacancy and a self-interstitial titanium atom depend on both the number of helium atoms and the helium-to-vacancy ratio(n/m) of *** thermal stability of clusters is decided by the competitive processes among thermal emissions of vacancy,SIA and helium atom.
High-spin states in Rb84 have been studied by using the Zn70(O18,p3n)Rb84 reaction at beam energy of 75 MeV. The γ-γ coincidence, excitation function, and ratios for directional correlation of oriented states were d...
High-spin states in Rb84 have been studied by using the Zn70(O18,p3n)Rb84 reaction at beam energy of 75 MeV. The γ-γ coincidence, excitation function, and ratios for directional correlation of oriented states were determined. A new level scheme was established in which the positive- and negative-parity bands have been extended up to 17+ and 17− with an excitation energy of about 7 MeV. The signature splitting and signature inversion of the positive-parity yrast band were observed. To understand the microscopic origin of the signature inversion in the yrast positive-parity bands of doubly odd Rb nuclei, as an example, we performed calculations using the projected shell model to describe the energy spectra in Rb84. It can be seen that the main features are reproduced in the calculations. This analysis shows that the signature splitting, especially its inversion, can be reproduced by varying only the γ deformation with increasing spin. To research the deformation of Rb84 carefully, we calculate the total Routhian surfaces of positive-parity yrast states by the cranking shell model formalism. In addition, the results of theoretical calculations about the negative-parity yrast band in Rb84 with configuration π(p3/2,f5/2)⊗νg9/2 are compared with experimental data, and a band diagram calculated for this band is also shown to extract physics from the numerical results.
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