The aim of the work was to study the nature of unstable luminescence of nitride bulk layers and heterostructures under stationery electron beam irradiation. During irradiation increasing of intensity of luminescence was observed. Typical times of this effect are tens up to hundreds of seconds. Details of the effect were studied. It was noticed that in several cases the irradiated by electron beam area was characterized by different luminescence properties even after 24 h at room temperature in vacuum. Several mechanisms leading to increasing of the intensity of luminescence were discussed.

The aim of this work was development of electron probe microanalysis (EPMA) technique suitable for composition determination of nanoscale layers. Proposed technique allows to determine the content of thin layers lying beneath the surface including single quantum wells (SQWs). The method is based on Monte‐Carlo numerical simulations. Application of this technique to the nitride heterostructures with SQWs and multiple quantum wells (MQWs) was demonstrated. Peculiarities of the method are discussed. Electron trajectories in GaN sample with In0.1Ga0.9N single quantum well. Simulation was made by Monte‐Carlo method.

In the practice of hydrodynamic modeling the anisotropy parameter (the ratio of vertical permeability to horizontal – kv/kh) is usually determined by experts as a fixed value varying in the range of 0.1-0.01, for the formation or for the field as a whole, and it is specified in the adaptation process of the model to the development history. This approach is applicable and is successfully used for deposits characterized by low degree of lateral heterogeneity. However, at the present time, a significant number of deposits are in development, the productive layers of which were formed in continental and coastal-marine environment, and therefore are distinguished by a complex geological structure due to high lateral and vertical anisotropy. For such objects the use of the conventional approach with a fixed value of kv/kh leads to an incorrect consideration of the influence of the heterogeneity on effective vertical permeability. Thus, the necessity of an alternative method for constructing the kv/kh cube, recommended for use in the complex structure of reservoirs, is obvious. The paper proposes a method for calculation the anisotropy parameter in 3D model cells intersected by wells as the multiplication result of the true anisotropy coefficient by the coefficient of pseudoanisotropy, which is modeled in the interwell space differentially for the facies zones by the method of cosimulation with NTG, reproducing the heterogeneity of the formation structure. The coefficient of true anisotropy is defined as the arithmetic average value from the results of core studies. The pseudoanisotropy coefficient characterizes the vertical heterogeneity of the formation within a single cell of a 3D grid. It is calculated for cells intersected by wells as a ratio of vertical permeability, which is the result of the geometric averaging of well log interpretation values, to lateral permeability, determined as the result of the arithmetic averaging [1]. For other cells of the 3D grid the anisotropy parameter is modeled by the method of cosimulation with NTG, which correlates with pseudoanisotropy coefficient. The use of the proposed method for modeling of anisotropy cube in process of hydrodynamic calculations allows to take into account the influence of heterogeneity on the effective vertical permeability differentially for facies zones and sedimentological units within facies zones.

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Durable crystalline actinide host phases of ceramic waste forms are considered as advanced materials which are prospective for safe use of Pu and minor actinides before their final disposal. Development of self-glowing actinide-doped materials with matrices that are chemically inert and resistant to radiation damage may significantly change the approaches to actinide immobilization. Single crystals of zircon doped with different amount of Tb and 238 Pu were synthesized by the flux method. Different non-radioactive crystals of Tb-doped zircon were studied first by cathodoluminescence method in order to identify the optimal content of Tb 3+ that provides the highest luminescence emission. Then self-glowing crystals of zircon were grown with the optimal Tb content and small admixture of 238 Pu (less than 0.1 wt. %). It was proposed that the valence state of Tb incorporated into zircon crystals can be (3+) and (4+), but only trivalent Tb is responsible for intensive luminescence. It is demonstrated that a small addition of Zr-phosphate to the flux supports Tb incorporation into zircon lattice and stabilizes preferably Tb 3+ . At the same time the addition of Zr-phosphate caused the crystallization of zirconia as a minor phase. Zircon crystals with very intensive self-glowing were successfully synthesized. The 238 Pu content was 0.02 wt.% and the Tb concentration varied between 0.2 and 0.3 wt.%. Zirconia crystals obtained from the same experiment are characterized by weak self-glowing, although the Tb content was only 0.02 wt.%, while the content of 238 Pu was comparable to that of zircon, i.e. 0.03 wt. %.