Adjustment of the Parameters in the Calculations of the γ-Production Data

Introduction The γ-production data are very important for the nuclear engineering, especially for the calculations of the radiation shielding. Because the experimental values of the γ-production data can not satisfy the needs of the nuclear engineering both in the quantity of the nuclei and in the energy region covered by them, as the supplement, the theoretical calculations of the γ-production data are indispensable. The γ-production data in the nuclear reactions induced by neutrons include the γ-production cross sections, the γ-energy spectra, the γ-multiplicities and the reaction cross sections of the (n,γ) and the (n,xγ) reactions, where the (n,xγ) reactions mean     

Influence of the Electron Emission on the Properties of the Cathode Sheath

There are many cathode electron emission mechanisms which have been discussed [1]. But in arc discharge ) the thermionic and the field emission playan important role. The electron emission has influence on the properties of cathode fall region, whichcan be divided into two subzonesf space charge zoneand ionization zone [21. In this paper, the spacecharge zone is called cathode sheath (CS). The cathode sheath, being nearest to the cathode surface, isaffected by the electron emission first. Th…     

Substantiation of the Choice of Threshold Parameters for the System Monitoring the Fuel-Containing Materials in the Object “Cover”

A substantiation is given for the choice of threshold values of the neutron flux density (threshold-1 – Attention and threshold-2 – Danger), and formulas are derived for calculating these values for systems which are being designed and are currently in operation for monitoring the state of fuel-containing materials in the object Cover at the Chernobyl nuclear power plant.     

Study on the Manufacture Technology of the Zirconia Tubes Ⅲ.Research on the Slip Casting Process of the Zirconia Tubes

ThepropertiesofZrO2·Y2O3·Gd2O3slipwithintermediatediameter(therawmateri-alsunder1μmindiameterexceed60%)arestudiedinthepaper.Theslipcastingisper-formedusingplastermould.Itisfoundthatseveralfactors,includingthepHvalueofsus-pensionslip,theconcentrationofd…     

Mass-Spring Model Used to Simulate the Sloshing of Fluid in the Container Under the Earthquake

The fluid in the container interacts with the container structure under the earthquake, and the bottom and the side walls are subjected to the pressure because of the fluid sloshing. This pressure is called hydrodynamic pressure. The one dimensional lumpe…     

Analysis of the measurement field of the optical klystron

The measured fields of the optical klystron in NSRL (National Sychrotron Radiation Laboratory)are, given, incluing the distribution on the axis,and the integrated filed distribution.the harmonic magnet fild and the spectra of the spontaneous emission are analyzed,and the multiple fild is presented by fitting the diagram.The influence of the integrated fild on the colse orbit of the beam and on the operation parameters of the storage ring ,and the compensation in the oexperiment are also discussed.     

Mass-Spring Model Used to Simulate the Sloshing of Fluid in the Container Under the Earthquake

The fluid in the container interacts with the container structure under the earthquake, and the bottom and the side walls are subjected to the pressure because of the fluid sloshing. This pressure is called hydrodynamic pressure. The one dimensional lumped mass-spring model（LMSM） is presented in ＂Seismic Analysis of Safety related Nuclear Structures and Commentary on Standard for Seismic Analysis of Safety related Nuclear Structures＂ （ASCE 4—86）. This model, which is simple but valid, is described in detail. This paper develops 3-D mass-spring model based on the LMSM in the ASCE 4—86.     

Study on the focusing properties of the Accelerating Tube

1.IntroductionAnacceleratingtubemadeup0fcylinderelectrodesisanelectrostaticlenssystem,inwhichtheionpathissimilartothatinopticlens.Manypapershavebeent0uchedonit,butveryseldomin-volvedwithanin-depthdiscussi0ni0nonfocusingpropertiesofanacceleratingtube[l~4].ThispapergivesasimpledtherentiaImethod,bywhichtheionpathisintegratedwithaunitelectr0staticlens,anddiscussesthefocusingpropertiesofthetube.2.BasicequationsofaunitlensTwocyllnderelectrodesmakeupaunitelectro-staticlens.Fortheweaklensapproximati…     

Revisiting the Effects of Compressibility on the Rayleigh-Taylor Instability

The effects of compressibility on the Rayleigh-Taylor instability （RTI） are investigated. It is shown that the controversy over compressibility effects in the previous studies is due to improper comparison, in which the density varying effect obscures the real role of compressibility. After eliminating the density varying effect, it is found that the compressibility destabilizes RTI in both the cases of constant density and exponentially varying density when M 《1. This destabilizing effect is more important at smaller values of the Atwood number AT or greater values of gravity g, and the increment in the growth rate produced by compressibility depends inversely on the pressure p or the ratio of specific heat F.     

Investigation of the radiation characteristics of the masonry in the ai uranium–graphite reactor

The results of investigations of the nuclear safety of the masonry in the AI uranium–graphite (Industrial Association Mayak) reactor are presented. It is concluded on the basis of these results that the masonry is nuclear safe and a radiation certificate is composed. The radiation examination made it possible to determine the level, composition, and distribution of the radioactive contamination of the masonry as well as the level and distribution of the neutron and γ radiation, and to construct a forecast of the change in the activity of radionuclides in graphite as a function of the holding time. These data are necessary for safety analysis and for making decisions about the subsequent stages of decommissioning of the reactor. Translated from Atomnaya énergiya, Vol. 105, No. 5, pp. 266–269, November, 2008.     

Discussion on the Non-Equilibrium Phase of the Gliding Arc Plasma Driven by the Transverse Magnetic Field

a gliding arc driven by the transverse magnetic field was ignited between the electrodes with a complicated shape at atmospheric pressure and a non-equilibrium plasma was gencrated. Under our experimental conditions, a phenomenon was clearly observed where the arc power decreased with the increase in arc voltage. As the arc voltage was higher than 3.375 kV, the are power acquired from the power supply decreased, and the arc plasma began to switch to a non-equilibrium phase. The existence of the non-equilibrium arc plasma was very short, about 10 ms in one gliding arc discharge cycle.     

Experiment for the Flow Distribution in the CARR Fuel Assembly

CARR fuel assembly is a plate type fuel element, which has twenty rectangle coolant channels formatted by twenty-one fuel plates. The breadths of channel are symmetrically distribution along the     

Research of the CICC Stability by the Numerical Code Gandalf

1. IntroductionIn this zpaper, we introduce cable--in-conduit conductor (i.e. CICC) which is used in the HT--7U superconducting TOkamak to obtain an effective andstable superconductor design for large magnets. Thedesign of the HT-7U superconducting TOkamak incorporates superconducting magnets of the toroidalfield (TF) and poloidal field (PF) systems [1]. TheCICC is cooled with a forced -flow supercritical helium at 4.5K. One of the most key problems relatedto conductor and coil prote…     

Determination of the Trigger-Electrode Position for the Field-Distortion Spark Gap

The optimal axial position of the trigger-electrode of the field-distortion spark gap is investigated through electric field calculation.The electric fields of the gap are calculated when locating trigger-electrode at different positions.It is shown that if the distance d between the trigger electrode and the low electric potential electrode is greater than 1.3mm,the maximum field intensity occurs at the edge of the trigger-electrode ,which will facilitate the generation of multi-channel discharge.According to calculated results,the working characteristics of the gap is investigated and it shows that when d=1.4mm the field distortion gap can be triggered reliably.     

Unfolding the measured neutron spectra in the irradiation chamber of the UZrH reactor using iterative method

In the procedure of neutron fluence measurement in the whole energy range （10^-4 eV-18 MeV）, in the irradiation chamber of a UZrH reactor, the neutron energy spectra are unfolded using the method of minimizing directed divergence and SAND-II, which are used broadly at home and abroad. These methods belong to the iterative methods. In this article, the procedure of the spectra unfolding using the two methods is described in detail. The neutron spectrum distribution unfolded by the two methods agree well with each other. In the end, the major differences of the two iterative methods are compared with each other, and the main factors affecting the accuracy of the spectra unfolding with the iterative method are discussed.     

Brief Report on the Testing Calculation of the Fission Rate for the ~(238)U

The fission rate, P_f, for the ~(238)U produced by a 14 MeV neutron source at thecenter of a uranium mental is a very important factor of the fission system.Several experiments were to measure the factor. In 1960's, a famous experimentwas made by J.W. Weale in the Atomic Weapons Research Establishment of     

A Comparison of the Maximum Entropy Method of Analysis with the Exciton Model Plus the Master Equation

The maximum entropy method of analysis is successful in fitting experimental data.In order to reveal the underlying physics,this method is applied in comparison with the conventional approach,i.e the exciton model plus the master equation,to three cases.It is found that both approaches produce almost equally good fits to spectra,and yield almost the same average exciton numbers. This implies that there must be similar physical ideas behind the two approaches,and it should be safe to use the maximum entropy method of analysis to fit data or to estimate reaction cross sections.     

Influence of the Gas Mixture Ratio on the Correlations Between the Excimer XeCl Emission and the Sealed Gas Temperature in DIelectric Barrier Discharge Lamps

For dielectric barrier discharge lamps filled with various gas mixture ratios,the correlations between the excimer XeCl emission and the sealed gas temperature have been founded,and a qualitative explication is presented.For gas mixture with chlorine larger than 3%,the emission intensity increases with the sealed gas temperature,while with chlorine about 2%,the emission intensity decreases with the increase in the gas temperature,and could be improved by cooling water .However,if chlorine is less than 1.5% ,the discharge appears to be a mixture mode with filaments distributed in a diffused glow-like discharge,and the UV emission is independent on the gas temperature.