Measurement of Neutron Capture Cross Section for ~(71)Ga

The excitation curve for ~(71)Ga(n,γ)~(72)Ga reaction has been measured from 0.2 to 2.0 MeV by different authors. All of these measured cross sections are not in very good agreement with each other. To clarify the discrepancy it is necessary to measure the cross sections for ~(71)Ga(n,γ)~(72)Ga reaction again.     

Measurement of Thermal Neutron Cross Section of ~(135)Cs

The thermal neutron cross sections of the long-lived fission products are important for the study of nuclei structure,partitioning-transmutation of radioactive waste,neutron activation analysis,and so on. 135Cs emits pure β ray,and it has a half-life of …     

The Small Angle Scattering Cross Sections of 14.7 MeV Neutron for ~(238)U

This work is the continuation and the development of the previous researchwork.The main detector is a position sensitive neutron detector whichconsists of a long cylindric liquid scintillation tube and two photomultipliers atboth ends of the tube.The position imformation of the incident neutron isextracted by the time difference between the signals from the two photomultipliers.Recently the measurement have been done on the Cockcroft accelerator in Tsing-hua University.Special attention has been paid to the improvement of the relia-bility and the precision in the measurements.     

Measurement of ~(36)Cl With Gas-Filled Time-of-Flight Method

Some improvements of the gas-filled time-of-flight detector system were achieved. The thickness of the entrance window is decreased to 0.5 micron. A larger area surface barrier detector with the diameter of 40 mm was used to enlarge the detection efficien…     

A New Method for Measurement of Helium Mass Flow Rate in the Cryogenic System of TORE SUPRA

The TORE SUPRA Tokamak was built by EURATOM-CEA association. The NbTi conductor of superconducting coils is inserted in a tight enclosure filled with pressurized superfluid helium of 0.125 MPa at 1.8 K. The thick casing is cooled to 4.5 K by 1.8 MPa in 4.5 K supercritical helium circulation. Around this thick casing, a 80 K thermal shield protects the parts at very low temperatures from the thermal radiation, which is cooled by pressurized helium at 80 K and 1.8 MPa. A new measurement method for helium mass flow rate of 80 K shield and 4.5 K casing is described in this paper. The commissioning was done on the two helium loops of the cryoplant: the supercritical 4.5 K thick casing and 80 K shields. The purpose is to improve control of the 4.5 K and 80 K refrigeration loops.     

Activation Cross Section Measurement for the Eu(n,γ) Reactions

The cross sections for ~(151)Eu(n,γ)~(152m)Eu, ~(151)Eu(n,γ)(152g)Eu and ~(153)Eu(n,γ)~(154)Eu reactions have been measured relatively to that of ~(197)Au for neutron energy from 22 to 1100 keV, using the activation technique. Neutrons were generated via the ~7Li(p,n)~7Be and T(p,n)~3He reaction with a 4.5 MV Van de Graaff accelerator at Peking University. The activities after irradiation were measured with two calibrated high resolution HPGe detectors. The accuracy of the measurement is 6～7%. The experiment results were compared with existing data.     

Thermal hydraulic and safety analysis for core conversion (HEU–LEU) of Syrian Miniature Neutron Source Reactor

The paper presents the behavior and properties analysis of the low enriched uranium fuel compared with the original high enriched uranium fuel. The MNSR reactor core was modeled with both fuel materials and the reactor behavior was studied during the steady state and abnormal conditions. The MERSAT code was used in the analysis. The steady state thermal hydraulic analysis results were compared with that obtained from the experimental results hold during commissioning the Syrian MNSR. Comparison with experimental data shows that the steady-state behavior of the HEU core was accurately predicted by the MERSAT code calculations. The validated model was then used to analyze LEU cores with two proposed UO₂ fuel pin designs. With each LEU core, the steady state and 3.77 mk rod withdrawal transient were run and the results were compared with the available published data in the literatures for the low enriched uranium fuel core. The results reveal that the low enriched uranium fuel showed a good behavior and the peak clad temperatures remain well below the clad melting temperature during reactivity insertion accident.     

Measurement of Cross Section for ~(92)Mo(n,p)~(92m)Nb Reaction and Deduction of Low Energy Neutron

Introduction Molybdenum is an important component of structural material for fission and future fusion reactors. It consists of seven isotopes. Therefore, fast neutrons can lead to many nuclear reactions. One of them is ~(92)Mo(n,p)~(92m)Nb reaction. Several authors published their data for this reaction, while most of the cross section determinations were     

Measurement of Thermal Neutron Cross Section of 137Cs(n, γ)138Cs Reaction

A calculational model for a modified diffusion coefficient has been developed to incorporate the neutron streaming effect in heterogeneous low-density channels accurately into diffusion theory calculations. The model uses a supercell, and the axial and radial diffusion coefficients of the heterogeneous inner cell are so defined that they can reproduce Benoist's axial and radial diffusion coefficients of the supercell when the diffusion coefficient of the outer cell is given as 1/3 Σ_tr . In the case of the axial diffusion coefficient, the axial buckling effect is taken into account by modifying the neutron path length within the streaming channel in calculating the collision probabilities. This model has been applied to an RZ fast reactor Core model with a gas expansion module (GEM). By using the axial diffusion coefficient obtained with the presented model, calculational error of GEM worth was reduced to less than 1/7 compared to the formula of Rowlands and Eaton.     

Theoretical Calculation of Neutron Cross Sections for ~(176)Hf

Neutron activation cross sections calculation for ~(176)Hf in the neutron energy below 20 MeV is carried out with UNF code. The calculated cross sections for (n,γ), (n,p), (n,α), (n,d), (n,t), (n,2n) and (n,3n) reaction are given. The results of the calculation are compared with the available experimental data and a good agreement is obtained. The calculation is also compared with the relevant evaluation data.     

Preparation of ~(151)Sm Standards for AMS Measurement

151Sm (T1/2=90 a) is a kind of long-lived fission products. It was applied to the industry, agriculture, national defence and many other fields. The measurement of 151Sm is very significant in environment     

Measurement of ~(90)Sr in Soil Samples With a Pure Instrumental Method

A pure instrumental method of 90Sr determination in soil samples is developed in order to meet fast measurement of batch soil samples. Gamma-ray spectrum of soil samples and the bremsstrahlung effect     

Measurement and theoretical evaluation of cross section for Na(4D) Na(3S)→Na(4F) Na(3S)

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Method of ~(151)Sm Measurement With AMS——Study on Chemical Form of Sample

151Sm (T1/2=90 a) belongs to the rare earths, it has important implications in the industry, agriculture and national defence etc. The study about its influences on environment and health is also a very important object. But the content of Sm in samples i…     

Chemical Form of Selection for ~(79)Se Measurement With AMS

79Se is a long-lived radionuclide which is produced from nuclear waste, and the half-life is (2.80±0.40)×105 a. Recently, owing to the potential implications of Se in the field of biomedical research and environment science research, measuring the content of the trace element79Se in the biological     

Measurement of (d,p) and (d,α) differential cross-sections for aluminum

The differential cross-sections for ²⁷Al(d,p_{0+1,2+3,4,5+6})²⁸Al and ²⁷Al(d,α_0,1,2,3,4)²⁵Mg have been measured in the energy ranges from 1.3 to 2.3 MeV and from 1.5 to 2.4 MeV, respectively at the laboratory angle of 150°. The obtained results are compared with data published in the literature. Discrepancies between new and previously acquired data are discussed. The cross-sections measured in the present work were uploaded to the IBANDL data base (www-nds.iaea.org/ibandl/).     

Indirect Measurement of Astrophysical S(E) Factor for ~9Be(p,α)~6Li Reaction by Means of the Trojan Horse Method

The beryllium abundance acts as a key role for understanding the inhomogeneous Big Bang nucleosynthesis. In order to measure the 9Be(p, α)6Li bare nucleus cross section and S(E) factor at astrophysical energies, the Trojan Horse Method (THM) can be appli…     

Measurement of Activation Cross Sections for ~(159)Tb(n,γ)~(160)Tb and ~(169)Tm(n,γ)~(170)Tm Reactions

Introduction Both ~(159)Tb and ~(169)Tm are rare-earth elements. Their activation cross sections are a good indicator for nuclear science and technology applications. Precise values of the neutron capture cross section of terbium and thulium also are of practical importance in relation to reactor design since they are the fission product poisons.