Benchmarking of Uranium-238 Evaluations against Spherical Transmission and (n,xn)-Reaction Experimental Data

Abstract. The double differential cross sections for the U(n,xn) reaction at 14 MeV and neutron leakage spectra from the uranium sphere of 24 cm outer and 8 cm inner diameters with the central T-D and 252 Cf neutron sources measured at the Institute of Physics and Power Engineering were used for benchmarking the evaluated cross sections from ENDF-B6, JEFF-3.0, and "Maslov" libraries and preliminary versions of JEFF-3.1 and ENDF-B7 evaluations for 238 U

Lower Temperature Annealing of Vapor Diffused Nb\u3csub\u3e3\u3c/sub\u3eSn for Accelerator Cavities

Nb3Sn is a next-generation superconducting material for the accelerator cavities with higher critical temperature and superheating field, both twice compared to Nb. It promises superior performance and higher operating temperature than Nb, resulting in significant cost reduction. So far, the Sn vapor diffusion method is the most preferred and successful technique to coat niobium cavities with Nb3Sn. Although several post-coating techniques (chemical, electrochemical, mechanical) have been explored to improve the surface quality of the coated surface, an effective process has yet to be found. Since there are only a few studies on the post-coating heat treatment at lower temperatures, we annealed Nb3Sn-coated samples at 800 C - 1000 C to study the effect of heat treatments on surface properties, primarily aimed at removing surface Sn residues. This paper discusses the systematic surface analysis of coated samples after annealing at temperatures between 850 C and 950 C

Management of the Synchronous Machine of Electromagnetic Excitation of Electric Drive

В работе рассматривается применение метода синтеза многомерного управления синхронной машиной с электромагнитным возбуждением быстродействующего электропривода. Используя вариационные методы и метод обратной модели для нелинейного многомерного объекта, организованное управление обеспечивает типовой характер формирования электромагнитного момента при минимизации тепловых потерь в условиях минимума реактивной мощности, учитывая нелинейность характеристики намагничивания синхронного двигателя. Быстрое изменение тока ротора в условиях ограничения напряжения достигается за счет использования размагничивающего действие реакции якоря. Представлены результаты моделирования. Потери в стали не учитываются.The paper considers the application of the method for synthesizing multidimensional control of a synchronous machine with electromagnetic excitation of a high-speed electric drive. Using variational methods and the inverse model method for a nonlinear multidimensional object, organized control provides a typical character of the formation of an electromagnetic moment in minimizing heat losses in conditions of minimum reactive power, taking into account the nonlinearity of the magnetization characteristic of a synchronous motor. A rapid change in the rotor current under voltage-limiting conditions is achieved by using the effect of the demagnetizing action of the armature reaction. The results of modeling are presented. Losses in steel are not taken into account