Effective thickness of the planar detector in measurements of electrons energy loss

An experimental method of determining the active region thickness of Si planar detector was used. The method based on the dependence the depletion layer thickness from voltage applied to the detector (U = 0...60 V ). The electron energy loss spectra emitted by ⁹⁰Sr -⁹⁰Y in silicon planar detector were measured. The relative values of most probable energy loss of electrons were de ned for different thickness of detector. The planar detector was considered as a parallel-plate capacitor. The static (capacity) and dynamic (the detection efficiency and the energy deposit) characteristics had a root dependence on voltage.Використовувався експериментальний метод визначення товщини активної області Si-планарного детектора. Метод заснований на залежності товщини збідненого шару від напруги, прикладеної до детектора (0...60 В). Вимірювалися спектри втрат енергії електронів, що випускаються ⁹⁰Sr -⁹⁰Y в кремнієвому планарному детекторі. Були визначені відносні значення найбільш ймовірних втрат енергії електронів для різної товщини детектора. Плоский детектор розглядався як конденсатор з паралельними пластинами. Статична (ємність) і динамічна (ефективність реєстрації та енергетичні втрати) характеристики мають кореневу залежністю від напруги.Использовался экспериментальный метод определения толщины активной области Si-планарного детектора. Метод основан на зависимости толщины обедненного слоя от напряжения, приложенного к детектору (0...60 В). Измерялись спектры потерь энергии электронов, испускаемые ⁹⁰Sr -⁹⁰Y в кремниевом планарном детекторе. Были определены относительные значения наиболее вероятных потерь энергии электронов для различной толщины детектора. Плоский детектор рассматривался как конденсатор с параллельными пластинами. Статическая (емкость) и динамическая (эффективность регистрации и энергетические потери) характеристики имеют корневую зависимостью от напряжения

Bremsstrahlung of electrons and yield of neutrons from thick converters, passing of gamma-radiation and neutrons through biological shielding

In GEANT4 spectral-angular distributions of the bremsstrahlung of medium-energy electrons from amorphous targets of different thickness and atomic charge were calculated. The total yield of gamma quanta in the forward hemisphere and at large scattering angles were determined depending on the converter thickness. The difference in the characteristics of gamma radiation for thin and thick targets was shown. The neutron yield is calculated due to photonuclear reactions for various converters. Numerical estimates of the radiation spectra after passing through the biological shielding for neutron and bremsstrahlung were carried out.У GEANT4 розраховано спектрально-кутові розподіли гальмівного гамма випромінювання електронів середніх енергій з аморфних мішеней-конверторів різної товщини і атомного заряду. Визначено повний вихід гамма-квантів у передню півсферу і під великими кутами розсіювання в залежності від товщини конвертора. Показано відмінність характеристик гамма-випромінювання для тонких і товстих мішеней. Проведено розрахунок виходу нейтронів за рахунок фотоядерних реакцій для різних конверторів. Проведено чисельні оцінки спектрів випромінювання після проходження біологічного захисту окремо для нейтронного і гальмівного випромінювань.В GEANT4 рассчитаны спектрально-угловые распределения тормозного гамма-излучения электронов средних энергий из аморфных мишеней-конверторов различной толщины и атомного заряда. Определен полный выход гамма-квантов в переднюю полусферу и под большими углами рассеяния в зависимости от толщины конвертора. Показано различие характеристик гамма- излучения для тонких и толстых мишеней. Проведен расчет выхода нейтронов за счет фотоядерных реакций для различных конверторов. Проведены численные оценки спектров излучения после прохождения биологической защиты отдельно для нейтронного и тормозного излучений

Soliton Squeezing in a Mach-Zehnder Fiber Interferometer

A new scheme for generating amplitude squeezed light by means of soliton self-phase modulation is experimentally demonstrated. By injecting 180-fs pulses into an equivalent Mach-Zehnder fiber interferometer, a maximum noise reduction of $4.4 \pm 0.3$ dB is obtained ($6.3 \pm 0.6$ dB when corrected for losses). The dependence of noise reduction on the interferometer splitting ratio and fiber length is studied in detail.Comment: 5 pages, 4 figure

Research of the Effectiveness of Using Air and Ground Low-grade Heat for Buildings Heating in Different Regions of Russia

The article presents the results of research on zoning of the Russian Federation based on efficiency of utilization of the low-grade heat of ground and air as well as combinations thereof for heating buildings. When modeling thermal behavior of geothermal HHS in the climatic conditions of various regions of the Russian Federation we considered the effect of long-term recovery of geothermal heat on the thermal behavior of the ground, as well as the effect of the ground pore water phase transitions on the operational efficiency of geothermal heat pump heating systems. The zoning took into account temperature drop of the ground mass caused by many years of heat recovery from the ground. Ground temperatures expected for the 5th year of geothermal HHS operation were used as design ground mass temperatures

Simulation of the Low-Emissive Coatings Influence on Double-Glazed Windows Thermal Parameters

This paper presents a one-dimensional dynamical model, based on the heat balance equations and calculations of thermal parameters for triple-glazed windows with various low-emissive coatings. The described study was performed with the financial support of the Ministry of Education and Science of Russia. Contract ID RFMEFI57614X0034

Modelling of Thermal Behavior of Borehole Heat Exchangers of Geothermal Heat Pump Heating Systems

This article reports results of comparing the accuracy of the software package “INSOLAR.GSHP.12”, modeling non-steady thermal behavior of geothermal heat pump heating systems (GHCS) and of the similar model “conventional” using finite difference methods for solving spatial non-steady problems of heat conductivity. The software package is based on the method of formulating mathematical models of thermal behavior of ground low-grade heat collection systems developed by INSOLAR group of companies. Equations of mathematical model of spatial non-steady thermal behavior of ground mass of low-grade heat collection system obtained by the developed method have been solved analytically that significantly reduced computing time spent by the software complex “INSOLAR.GSHP.12” for calculations. The method allows to turn aside difficulties associated with information uncertainty of mathematical models of the ground thermal behavior and approximation of external factors affecting the ground. Use of experimentally obtained information about the ground natural thermal behavior in the software package allows to partially take into account the whole complex of factors (such as availability of groundwater, their velocity and thermal behavior, structure and arrangement of ground layers, the Earth’s thermal background, precipitation, phase transformations of moisture in the pore space, and more), significantly influencing the formation of thermal behavior of the ground mass of a low-grade geothermal heat collection system. Numerical experiments presented in the article confirmed the high convergence of the results obtained through the software package “INSOLAR.GSHP.12” with solutions obtained by conventional finite-difference methods

Simulation of the Low-Emissive Coatings Influence on Double-Glazed Windows Thermal Parameters

This paper presents a one-dimensional dynamical model, based on the heat balance equations and calculations of thermal parameters for triple-glazed windows with various low-emissive coatings. The described study was performed with the financial support of the Ministry of Education and Science of Russia. Contract ID RFMEFI57614X0034

Assessment of impact of borehole heat exchanger design on heat extraction/rejection efficiency

The article considers the impact of design of borehole heat exchanger (BHE) as one of the main elements of a geothermal heat pump system on its efficiency in the ground heat extraction/rejection. Four BHE modifications are considered: coaxial with metal and polyethylene outside tube as well as single and double U-shaped structures of polyethylene tubes. Numerical modeling resulted to data on the efficiency of these BHE modifications for rejection heat into ground (heat pump system in cooling mode), and ground heat extraction (heat pump system in heating mode). Numerical values were obtained and BHEs were ranked according to their efficiency in both operation modes. Besides, additional calculations were made for the most common modification - double U-shaped design - in the ground heat extraction mode for various tube sizes with various wall thicknesses

Efficiency of Passive Utilization of Ground “Cold” in Adaptive Geothermal Heat Pump Heating and Cooling Systems (AGHCS)

This article deals with estimating a potential and efficiency of utilization of passive ground “cold” for cooling buildings in climatic conditions of Moscow (Russia). The article presents results of numerical analysis to assess the efficiency of reducing peak cooling loads of the building equipped with AGHCS, through the utilization of natural cold of wells for passive cooling and cold storage in summer at night (off-peak) time with its subsequent consumption in the day time, both in passive mode, and with heat pumps. The conclusions of the article set out the basic principles of passive cooling in the design of AGHCS