Calculation of production cross sections of γ-rays fromthermal-neutron captures

The calculation methods of production cross sections of y-rays for thermal-neutron captures are briefly presented. The check of intensity balance is made. The examples are given to illustrate its application.     

Calculation of production cross sections of γ-rays from thermal-neutron captures

The calculation methods of production cross sections of γ-rays for thermal-neutron captures are briefly presented. The check of intensity balance is made. The examples are given to illustrate its application.     

A method of analysing experimental data of nuclear reaction cross sections

A method of analysing experimental data of nuclear reaction cross sections σr induced by radioactive beam is described.It can be used in analysis of experimental unclear reaction cross section data obtained by Na-isopope radioactive beams on different targets.Neutron halo has not been found in these nuclei.     

Theoretical estimates of cross sections for neutron–nucleus collisions

We construct an analytical model derived from nuclear reaction theory and having a simple functional form to demonstrate the quantitative agreement with the measured cross sections for neutron induced reactions. The neutron–nucleus total, reaction and scattering cross sections, for energies ranging from 5 to 700 MeV and for several nuclei spanning a wide mass range are estimated. Systematics of neutron scattering cross sections on various materials for neutron energies up to several hundred MeV are important for ADSS applications. The reaction cross sections of neutrons are useful for determining the neutron induced fission yields in actinides and pre-actinides. The present model based on nuclear reaction theory provides good estimates of the total cross section for neutron induced reaction.     

Prediction of synthesis cross sections of new moscovium isotopes in fusion-evaporation reactions

In the framework of the dinuclear system model,the synthesis mechanism of the superheavy nuclides with atomic numbers Z=112,114,115 in the reactions of projectiles ^40,48 Ca bombarding on targets ²³⁸ U,²⁴²Pu,and ²⁴³ Am within a wide interval of incident energy has been investigated systematically.Based on the available experimental excitation functions,the dependence of calculated synthesis cross-sections on collision orientations has been studied thoro...     

Measurement of fast－neutron capture cross sections for ^75As

The cross sections of the ^75As(n,γ)^76As reaction were measured in the neutron energy range from 0.50 to 1.50 MeV by using the activation technique.Neutrons were produced via the T(p,n)^3He reaction and the cross sections of the ^197Au(n,γ)^198Au reaction were used to determine the absolute neutron flux.Present results are compared with existing measurements and evaluations.     

Measurements of Lα, Lβ X-ray production cross sections of Bi by 17-40 keV electron impact

We present results of measurements of L_α, L_β X-ray production cross sections for the element Bi (Z = 83) by 17-40 keV electron impact. The target used in the experiment was prepared by evaporating the element Bi to the thick pure carbon substrate. The effects of multiple scattering of electrons when penetrating the target film, of electrons reflected from the thick pure carbon substrate and of bremsstrahlung photons produced by the impact of incident electrons on the target are corrected by means of Monte Carlo simulation. The experimental data, reported here for the first time in the energy region of 17-40 keV, are compared with the DWBA theory and the PWBA-C-Ex theory. They are in good agreement.     

L1 and L2 sub-shell fluorescence yields for elements with 64 ? Z ? 70

The L₁ and L₂ sub-shell fluorescence yields have been deduced for elements with 64 ? Z ? 70 from the L_k(k = l, α, β_1,4, β_3,6, β_2,15,9,10,7, γ_1,5 and γ_2,3,4) X-ray production cross sections measured at 22.6 keV incident photon energy using a spectrometer involving a disc type radioisotope of Cd¹⁰⁹ as a photon source and a Peltier cooled X-ray detector. The incident photon intensity, detector efficiency and geometrical factor have been determined from the K X-ray yields emitted from elemental targets with 20 ? Z ? 42 in the same geometrical setup and from knowledge of the K shell cross sections. The present deduced ω₁(exp) values, for elements with 64 ? Z ? 70, are found to be in good agreement with those tabulated by Campbell (J.L. Campbell, Atom. Data Nucl. Data Tables 95 (2009) 115), where as these are, on an average, higher by 19% and 24% than those based on the Dirac-Hartree-Slater model (S. Puri et al., X-ray Spectrometry 22 (1993) 358) and the semi-empirical values compiled by Krause (M.O. Krause, J. Phys. Chem. Ref. Data 8 (1979) 307), respectively. The present deduced ω₂(exp) values are found to be in good agreement with those based on the Dirac-Hartree-Slater model and are higher by up to ∼13% than the semi-empirical values for the elements under investigation.     

Formation cross sections of nuclei with (n,2n) reactions

Ｆｏｒｍａｔｉｏｎｃｒｏｓｓｅｃｔｉｏｎｓｏｆｎｕｃｌｅｉｗｉｔｈ（ｎ，２ｎ）ｒｅａｃｔｉｏｎｓＣｈｅｎＸｕｅＳｈｉ，ＸｉｅＫｕａｎＺｈｏｎｇ，ＺｈｏｕＳｈｅｎｇＭｏ，ＹａｎＱｉｎｇＱｕａｎ（ＳｈａｎｇｈａｉＩｎｓｔｉｔｕｔｅｏｆＮｕｃｌｅ...     

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.     

Conceptual design of a Cs2LiLaBr6 scintillator-based neutron total cross section spectrometer on the back-n beam line at CSNS

To reduce the experimental uncertainty in the 235 U resonance energy region and improve the detection efficiency for neutron total cross section measurements compared with those obtained with the neutron total cross section spectrometer(NTOX), a dedicated lithium-containing scintillation detector has been developed on the Back-n beam line at the China Spallation Neutron Source. The Fast Scintillator-based Neutron Total Cross Section(FAST) spectrometer has been designed based on a Cs2Li La Br6(CL...     

Systematics studies of (n, α) reaction cross sections at 14.5 MeV neutrons energy

A new semi-empirical formula for the calculation of the (n, α) cross-section at 14.5 MeV neutron energy is obtained. It is based on the pre-equilibrium exciton and evaporation models and uses the Droplet model of Myers and Swiatecki to express the reaction energy Q(n, α). The systematics behavior of the different terms of the Droplet model involved in Q(n, α) was checked individually before choosing the pertinent terms and setting up the formula. Fitting this formula to the existing cross-section data, the adjustable parameters have been determined and the systematics of the (n, α) reaction have been studied. The predictions of this formula are compared with those of the existing formulae and with the experimental data. The formula with five parameters is found to give a better fit to the data than the previous comparable formulae.     

Measurements of fast—neutron capture cross sections for ^159Tb and ^169Tm

The neutron capture cross sections for ^159Tb and ^169Tm relative to the ^197Au (n,γ)^198Au reaction are measured at neutron energies of 0.57,1.10 and 1.60 MeV by using the activation method.The activities of the products are measured with a high resolution HPGe detector gamma-ray spectrometer.The errors of the present work are 5-6% for Tb,6-7% for Tm.The recommended data in energy region of 0.4-3.0MeV are given as compared with other data published previously.     

Deuteron–nucleus total reaction cross sections up to 1 GeV

Total reaction cross sections of deuteron, σ^R_d, are calculated by a microscopic three-body reaction model. The reaction model has no free adjustable parameter and applicable to reactions at various deuteron incident energies E_d and with both stable and unstable nuclei. The predicted σ^R_d are consistent with those evaluated by a phenomenological optical potential for E_d ? 200 MeV in which the potential has been parametrized. A simple formula of σ^R_d up to E_d = 1 GeV, as a function of E_d, the target mass number A and its atomic number Z, is given.     

Differential elastic scattering cross sections of protons from Al in 2.4–4.8 MeV energy range

Measurement of differential elastic cross section of protons from aluminum was taken at 165° degree in the2.4–4.8 Me V energy range. The results and measured energy resonances were compared with reported measurements.These data will improve the reliability of backscattering analysis of Al with protons in this energy region.     

Measurement of 8～25keV electron impact K－shell ionization cross sections of Cu and Co elements

Ｍｅａｓｕｒｅｍｅｎｔｏｆ８～２５ｋｅＶｅｌｅｃｔｒｏｎｉｍｐａｃｔＫ－ｓｈｅｌｌｉｏｎｉｚａｔｉｏｎｃｒｏｓｓｓｅｃｔｉｏｎｓｏｆＣｕａｎｄＣｏｅｌｅｍｅｎｔｓＡｎＺｈｕ（安竹），ＬｉＴａｉ－Ｈｕａ（李泰华），ＷａｎｇＬｉａｎｇ－Ｍｉｎｇ（王良明）...     

Measurement of 8—25keV electron impact K—shell ionization cross sections of Cu and Co elements

The influence of substrate of thin targets on ionization cross sections has been corrected by a new method based upon the bipartition model of electron transport.The measured cross sections for Cu element are in good agreement with existing experimental data and those produced by the empirical formula of Green and Cosslett.Cross sections for Co element are measured for the first time.     

Measurement of 134Xe(n,2n)133m,gXe reaction cross sections in 14-MeV region with detailed uncertainty quantification

A lead-shielded HPGe detector and offline γ-ray spectra of the residual product were used to measure the cross section(CS)and ratios of isomeric CS(σm/σg) in ¹³⁴Xe(n,2n)^133m,gXe reactions at different energies(13.5 MeV, 13.8 MeV, 14.1 MeV,14.4 MeV, 14.8 MeV) relative to the ⁹³Nb(n,2n)^92m Nb reaction CS. The target was high-purity natural Xe gas under high pressure. The T(d,n)⁴He reaction produces neutrons. TALYS code(version 1.95) for nuclea...     

含TBP-HNO3超临界CO2流体静态络合萃取U3O8

建立了一种快速降低萃取系统压力的静态络合萃取实验装置。在此装置上研究了含TBP-HNO₃超临界CO₂静态络合U₃O₈的快速气化测量方法,探索了含TBP-HNO₃超临界CO₂静态络合萃取U₃O₈的行为规律。