The calculation of the differential cross sections for recoil protons in 4He-p Scattering

The equation relating phase shift to energy given by the effective range theory for charged particle reactions and the effective range parameters which can well fit the experimental data of P-⁴He elastic scattering have been used to obtain the phase shifts and differential cross sections of protons in p-⁴He elastic scattering. Thereafter the differential cross section of recoil protons in ⁴He-p elastic scattering are calculated through the principle of detailed balance and compared with the experimental data and Rutherford cross sections. Better consistency between experimental and theoretical values than in previous work is achieved.     

Measurement of fast-neutron capture cross sections for 75As

1 INTRODUCTIONThe cross sections of the "As(n,7)"As reaction are boortant in evaluating theradiation damage of the material. EXPerimeats[1-6] and evaluations have been performedto deterAnne the "As(n, 7)"As reaction cross section, but there are large discrepanciesamong them especially in the MeV neutron energy region. Therefore, new eXPerAnent isneeded.2 EXPERIMENT DETAILSThe measuremenis were perfOrmed at the 4.5 MV Van de Grand accelerator of theInstitute Of Heavy Ion Phy…     

Measurement of the total neutron cross sections for250,251Cf

V. I. Lenin Scientific Research Institute of Atomic Reactors. Translated from Atomnaya Énergiya, Vol. 74, No. 1, pp. 72–75, January, 1993.     

1-2 MeV能区6Li(n,t)4He反应微分截面与截面的实验测量

利用屏栅电离室对1.05、1.54及2.25 MeV中子6Li(n,t)4He反应的微分截面与截面进行了实验测量.采用氚固体靶的T(p,n)3He反应产生准单能中子,用相对效率已知的BF3长中子管和238U裂变片相结合来测定绝对中子通量.将测量结果与已有数据进行了比较,1-2 MeV能区6Li(n,t)4He反应截面的分歧在一定程度上得到了澄清.     

Accurate universal parameterization of absorption cross sections II--neutron absorption cross sections

A recent parameterization (here after referred as paper I, Ref. [4]) of absorption cross sections for any system of charged ions collisions including proton -nucleus collisions, is extended for neutron-nucleus collisions valid from approximately 1 MeV to a few GeV, thus providing a comprehensive picture of absorption cross sections for any system of collision pair (charged and/or uncharged). The parameters are associated with the physics of the problem. At lower energies, the optical potential at the surface is important and the Pauli operator plays an increasingly important role at intermediate energies. The agreement between the calculated and experimental data is better than earlier published results.     

Measurement of Sc and V K—shell ionization cross sections by slow electron impact

Electron-induced Sc and V K-shell ionization cross sections,which are scarce have been obtained from measurement of KαX-ray emission cross sections at energies from near threshold to 25keV.The influence of substrate of thin targets on ionization cross sections has been corrected using the bipartition model of electron transprot.     

Depth resolution and recoil cross section for analyzing hydrogen in solids using elastic recoil detection with 4He beam

Two aspects of the elastic recoil detection technique for analyzing H and D are described; i) experimental factors which effectively limit the depth resolution in Al film, and ii) determination of the recoil cross section for H(⁴He, ⁴He)H and D(⁴He, ⁴He)D reactions in the range of 1.5–3.0 MeV energy of ⁴He. Both experimental and theoretical estimates of the depth resolution are presented and are in good agreement each other. The theoretical estimate therefore provides a reliable guide to find optimum resolution conditions. The recoil cross section for H is more than double the theoretical Rutherford scattering value and that for D becomes greater than 30 times Rutherford near the resonance energy of 2.1 MeV ⁴He.     

Reconstruction method of homogenized cross sections

The reconstruction method of homogenized cross sections in the direct response matrix method has been developed. In this reconstruction method, homogenized cross sections, which take into consideration the influences of neighboring fuel assemblies, can be reconstructed with the response relationship of incoming neutron partial currents and neutron production rates. Calculations for heterogeneous multi fuel assembly systems were done to verify the developed method. The thermal energy group fuel assembly cell-averaged homogenized cross sections reconstructed by this method agreed with those evaluated by the direct calculation of the whole system using the Monte Carlo method within 0.2%. The effect using the reconstructed fuel assembly cell-averaged homogenized cross sections in a conventional core analysis code using cross sections homogenized in a fuel assembly cell was also investigated. The results obtained showed that the analysis accuracy of k-infinity can be improved by using the cross sections reconstructed by the method. Because almost no influences on the analysis accuracy could be found related to the divided numbers of the surfaces and the angles, and the response relationship with neutron production rates of fuel rods or a fuel assembly cell-averaged neutron production rate, this reconstruction method is applicable to a conventional core analysis code using homogenized cross sections in a fuel assembly cell.