Revisiting neutron yield in table-top nuclear fusion driven by an intense femtosecond laser pulse interaction with the gas clusters

With the development of femtosecond (fs) laser technology, an fs laser pulse with 10s of Joule, even 100s of Joule energy is available and the focused laser intensity can be expected to induce the pure Coulomb explosion of the cluster with a much larger average radius than before. Meanwhile, the production of gas cluster with an average radius of upto 10s of nanometer has been possible. In this case, it is necessary to reinvestigate the feasibility of 109 n/shot neutron yield for the practical application in the intense fs laser-driven nuclear fusion. In this work, the neutron yield from the explosions of the D2 clusters of 6–20 nm average radius at the 0.5–100 J pulse energy and the CD4 clusters was investigated theoretically. It is found that the optimum neutron yield of 109 n/shot can be obtained at the laser energy and the cluster radius currently available. However, a clustered-gas jet with a large cross-section is demanded to match the proper plasma diameter.

Algorithm to select the voltage class for the gas field electricity supply system

The current algorithms and mathematical models to select the voltage class based on the theory of experimental planning are developed for industrial enterprises (overhead lines with a length of up to 10 km, a power of up to 20 MV, a radial arrangement with a transformation at the end of the line). They do not consider the features of gas fields (overhead lines with a length of up to 20 km and a capacity of 1 MV with a projected growth of up to 10 MV, a transmission network with one pass-through trunk line with distributed transformation along the line). Currently, to develop a mathematical model, the following factors are considered: the average length of the power line and the total load of an enterprise. The proposed models do not allow us to quantify the dynamics of the gas fields power supply system considering the multiple growth of the electrical load in each period of the life cycle. The purpose of this study is to develop a model to solve this problem. An extreme experiment has been carried out during the research. The following input data are set: the average length of the power line; the number of gas clusters; the growth rate of the electric load. The response function is the voltage class that is optimal for the minimum discounted cost. The authors suggest the regression model. In this model the “total load” factor is split into two components, they are gas clusters and growth rate of electric loads. The algorithm to select the optimal voltage class of a distribution grid is proposed. The dynamic experiment is carried out and the growth rate of electric loads in the regressive model is being changed while other factors are being unchanged. As a result, the optimal minimum of the discounted costs of the voltage class for each period of the field life cycle is obtained. The algorithm is implemented in “PRON” software. With the help of “PRON” software, the distribution grids of several operating gas fields in Western Siberia have been investigated. The optimal voltage class of a distribution grid of gas fields is 20 kV. The reliability of the results is verified by reference models of calculating discounted costs.

Hierarchical fragmentation in high redshift galaxies revealed by hydrodynamical simulations

High-redshift star-forming galaxies have very different morphologies compared to nearby ones. Indeed, they are often dominated by bright star-forming structures of masses up to 108 − 9 M⊙ dubbed «giant clumps». However, recent observations questioned this result by showing only low-mass structures or no structure at all. We use Adaptative Mesh Refinement hydrodynamical simulations of galaxies with parsec-scale resolution to study the formation of structures inside clumpy high-redshift galaxies. We show that in very gas-rich galaxies star formation occurs in small gas clusters with masses below 107 − 8 M⊙ that are themselves located inside giant complexes with masses up to 108 and sometimes 109 M⊙ . Those massive structures are similar in mass and size to the giant clumps observed in imaging surveys, in particular with the Hubble Space Telescope. Using mock observations of simulated galaxies, we show that at very high resolution with instruments like the Atacama Large Millimeter Array or through gravitational lensing, only low-mass structures are likely to be detected, and their gathering into giant complexes might be missed. This leads to the non-detection of the giant clumps and therefore introduces a bias in the detection of these structures. We show that the simulated giant clumps can be gravitationally bound even when undetected in mocks representative for ALMA observations and HST observations of lensed galaxies. We then compare the top-down fragmentation of an initially warm disc and the bottom-up fragmentation of an initially cold disc to show that the process of formation of the clumps does not impact their physical properties.

Development of Oil and Gas Projects Based on the Cluster Approach on the Example of the Irkutsk Oil Company

Currently, world experience in oil and gas production shows that long-term economic impact of the industry can only be achieved if high value-added production capacity is established. The article analyzed the role of oil and gas industry worldwide and in Russia, noting relatively low level of hydrocarbon processing in Russia. The article analyzed international experience of various forms of state participation in creation and support of oil and gas clusters. Main trends in the development of gas and chemical industry abroad have been identified. We analyzed the current strategy for the development of chemical and petrochemical complex up to 2030. The conclusion is made about the need for state support for large-scale projects to create clusters in the field of oil and gas production and refining. The article described main stages of the project to create an oil and gas cluster in the Irkutsk Region - a gas project of the Irkutsk Oil Company.

Protonated and Cationic Helium Clusters

Protonated rare gas clusters have previously been shown to display markably different structures compared to their pure, cationic counterparts. Here, we have performed high-resolution mass spectrometry measurements of protonated and pristine clusters of He containing up to 50 atoms. We identify notable differences between the magic numbers present in the two types of clusters, but in contrast to heavier rare gas clusters, neither the protonated nor pure clusters exhibit signs of icosahedral symmetries. These findings are discussed in light of results from heavier rare gases and previous theoretical work on protonated helium.

A swarm intelligence modeling approach reveals noble gas cluster configurations confined within carbon nanotubes

A swarm intelligence modeling approach together with the continuum approximation for carbon nanotubes unravels confinement effects for noble gas clusters.