Measurement of the neutron-induced total cross sections of ^(nat)Pb from 0.3 eV to 20 MeV on the Back-n at CSNS

The neutron-induced total cross sections of natural lead have been measured in a wide energy range(0.3 eV-20 MeV)on the back-streaming white neutron beamline(Back-n)at the China Spallation Neutron Source.Neutron energy was determined by the neutron total cross-section spectrometer using the time-of-flight technique.A fast multi-cell fission chamber was used as the neutron detector,and a 10-mm-thick high-purity natural lead sample was employed for the neutron transmission measurements.The on-beam background was determined using Co,In,Ag,and Cd filters.The excitation function of ^(nat)Pb(n,tot)reaction below 20 MeV was calculated using the TALYS-1.96 nuclear-reaction modeling program.The present results were compared with previous results,the evaluated data available in the five major evaluated nuclear data libraries(i.e.,ENDF/B-VIII.0,JEFF-3.3,JENDL-5,CENDL-3.2,and BROND-3.1),and the theoretical calculation curve.Good agreement was found between the new results and those of previous experiments and with the theoretical curves in the corresponding region.This measurement obtained the neutron total cross section of natural lead with good accuracy over a wide energy range and added experimental data in the resonance energy range.This provides more reliable experimental data for nuclear engineering design and nuclear data evaluation of lead.

AA型MCMB/Li_(1.04)Mn_(1.96)O_4电池的性能

研究了以Li1.04Mn1.96O4为正极,中间相碳微球(MCMB)为负极的AA型锂离子电池。在室温条件下,电池的1C放电容量达500mAh,比能量达到95Wh/kg和210Wh/L,循环400次时,其容量仍为初始容量的85%,并具有较好的倍率特性。55℃荷电贮存7天后仍具有较好的充放电性能。电池在170℃荷电放置的条件下,不起火爆炸。

Engineering Cu_(1.96)S/Co_(9)S_(8) with sulfur vacancy and heterostructure as an efficient bifunctional electrocatalyst for water splitting

Defect and interface engineering have been recognized as efficient strategies for developing high-performance electrocatalysts.However,it is still challenging to couple defect and interface engineering in transition metal sulfides and understand their dynamic evolution process during electrocatalysis.Herein,we developed one-step pyrolysis of bimetallic sulfide to construct S vacancy-rich Cu_(1.96)S/Co_(9)S_(8) heterostructure by controlling the critical decomposition temperature.The as-synthesized Cu_(1.96)S/Co_(9)S_(8) exhibits excellent bifunctional electrocatalytic performance,with a low overpotential of 99 and 200 mV at 10 mA cm−2 towards hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)in 1.0 mol/L KOH electrolyte,respectively.A symmetric two-electrode cell with Cu_(1.96)S/Co_(9)S_(8) delivered a current density of 10 mA cm^(−2) at a low voltage of 1.43 V and showed long-term stability for 200 h.A series of in/ex-situ techniques revealed that the electrochemical reconfiguration only appeared in the OER process,resulting in the CoOOH/CuO and SO42−species promoting OER performance.Meanwhile,the S vacancy and heterostructure interface in Cu_(1.96)S/Co_(9)S_(8) were proved to optimize the electronic structure and the adsorption of intermediates for HER by density function theory(DFT)simulations.This work provides a promising strategy to construct metal sulfides with rich defects and heterogeneous interfaces and understand their dynamic evolution process for electrochemical storage and conversion devices.

Nuclear Model Calculations on the Production of Auger Emitter 165Er for Targeted Radionuclide Therapy

Auger electron emitting radionuclides have potential for the therapy of small-size cancers because of their high level of cytotoxicity, low-energy, high linear energy transfer, and short range biologic effectiveness. Auger emitter 165Er (T1/2 = 10.3 h, IEC = 100%) is a potent nuclide for targeted radionuclide therapy. 165Er excitation function via 165Ho(p,n)165Er, 165Ho(d,2n)165Er, 166Er(p,2n)165Tm→165Er, 166Er(d,3n)165Tm→165Er, natEr(p,xn)165Tm→165Er and 164Er(d,n)165Tm→165Er reactions were calculated by ALICE/91, ALICE/ASH (GDH Model & Hybrid Model) and TALYS-1.2 (Equilibrium & Pre-Equilibrium) codes and compared to existing data. Requisite for optimal thicknesses of targets were obtained by SRIM code for each reaction.

Cross sections for 14 MeV neutron interaction with lutetium isotopes and their theoretical excitation functions

The cross-sections for the 175Lu(n,p)175Yb,175Lu(n,α)172Tm,176Lu(n,α)173Tm,175Lu(n,2n)174mLu,and 175Lu(n,2n)174gLu reactions at 13.57,14.0314.62,and 14.86 MeV neutron energies were measured using an activation technique.The theoretical excitation functions of these reactions were calculated using the Talys-1.95 code.The reaction cross-section data experimentally obtained were analyzed and compared with experimental data reported in the literature,data from five major evaluated nuclear data libraries of IAEA,and theoretical values based on Talys-1.95.The data obtained at some neutron energies agree with some of the data reported in the literature and theoretical values based on Talys-1.95.The consistency of the theoretical curves of excitation functions based on Talys-1.95 with the data obtained in this study and those reported in the literature is higher than that of the evaluation curves of excitation functions for the 175Lu(n,p)175Yb,175Lu(n,α)172 Tm,and 176Lu(n,α)173Tm reactions.This study is helpful because it provides new evaluated reaction cross-section data on lutetium(which is a fusion reactor material),improves the quality of neutron-induced reaction cross section data libraries,and advances the research on related applications.

^(159)Tb中子辐射俘获反应截面的理论计算

^(159)Tb中子俘获反应的研究对于核物理、核能应用及核天体物理领域具有重要意义,有助于深入理解重核的形成和演化过程以及提高相关核数据的精确性和可靠性。核数据库中,^(159)Tb(n,γ)^(160)Tb截面的评价数据少,且实验数据存在分歧。为了提高^(159)Tb中子俘获反应截面数据的准确性,进行了1 keV~10 MeV能量范围内的^(159)Tb(n,γ)^(160)Tb反应中子俘获截面的理论计算。利用TALYS-1.9程序,比较了不同能级密度模型下1 keV~1 MeV低能区的反应截面,发现ldmodel5模型与最近实验数据吻合度最高。同时,对ldmodel5下的平均辐射宽度参数进行了调整,结果表明,当Γγadjust设为0.9时,理论计算结果与实验数据最符合。通过选择合适的能级密度模型和参数调整,验证了TALYS在^(159)Tb(n,γ)^(160)Tb反应理论计算中的可靠性,计算得到的反应截面与大量实验数据吻合度良好。

Cross-sections of the ^(238)U(n,γ) ^(239)U reaction in the 3.0-7.0 MeV energy region measured by relative activation method

The reaction cross-sections of^(238)U(n,γ)^(239)U have been experimentally determined at neutron energies of6.117±0.119 MeV,4.626±0.086 MeV,and 3.622±0.348 MeV employing the relative activation approach along with the off-line γ-ray spectroscopy method.The D(d,n)3He reaction was utilized to obtain monoenergetic neutrons of the required energy,and the^(197)Au(n,γ)^(198)Au reaction cross-sections were adopted as the referential standard to ascertain the neutron capture cross-sections of^(238)U.Furthermore,the effects of low-energy scattered neutrons,neutron fluence fluctuations,counting of geometric corrections when measuring γ-rays,and neutron and γ-ray self-absorption caused by the sample thickness have been considered and revised in the present work.For a comparison with experimental results,the cross-sections of the^(238)U(n,γ)^(239)U reaction were calculated theoretically with the original parametric TALYS-1.9 program.The experimental measurements were in contrast to previous experimental re sults and the evaluation data available for ROSFOND-2010,CENDL-3.2 and ENDF/B-VIII.0.

利用TALYS和EMPIRE研究质子诱发钼靶核反应

利用加速器直接生产^(99)Mo和^(99m)Tc在核医学领域具有良好的发展前景,精确可靠的核反应数据对于同位素生产具有重要意义。本文通过对EXFOR数据库中^(nat)Mo(p,x)^(96m+g)Tc、^(100)Mo(p,x)^(99)Mo、^(100)Mo(p,2n)^(99m)Tc核反应截面实验数据进行分析,采用多项式拟合实验数据给出参考值。并利用TALYS-1.95和EMPIRE-3.2.3程序结合不同能级密度、预平衡发射等模型计算了40 MeV能量以下^(nat)Mo(p,x)^(96m+g)Tc、^(100)Mo(p,x)^(99m)Tc、^(100)Mo(p,2n)^(99m)Tc核反应的激发函数。对于^(nat)Mo(p,x)^(96m+g)Tc核反应,TALYS-1.95程序采用能级密度输入参数ldmodel 6时,preeqmode 1,2模型计算结果与实验数据符合最好。对于^(100)Mo(p,x)^(99)Mo核反应,TALYS-1.95程序采用能级密度输入参数ldmodel 6时,preeqmode 4模型计算结果与实验数据符合最好。对于^(100)Mo(p,x)^(99)Mo核反应,EMPIRE-3.2.3程序LEVDEN 2模型计算结果与实验数据符合最好。

Erratum:Measurement of(n,α)and(n,2n)reaction cross sections at a neutron energy of 14.92±0.02 MeV for potassium and copper with uncertainty propagation,[A.Gandhi,Aman Sharma,Rebecca Pachuau et al.,Chin.Phys.C 46,014002(2022)]

Experimentally measured neutron activation cross sections are presented for the^(65)Cu(n,α)^(62m)Cu,^(41)K(n,α)^(38)Cl,and^(65)Cu(n,2n)^(64)Cu reactions with detailed uncertainty propagation.The neutron cross sections were measured at an incident energy of 14.92±0.02 MeV,and the neutrons were based on the t(d,n)αfusion reaction.The^(27)Al(n,α)^(24)Na reaction was used as a reference reaction for the normalization of the neutron flux.The pre-calibrated lead-shielded HPGe detector was used to detect the residues'γ-ray spectra.The data from the measured cross sections are compared to the previously measured cross sections from the EXFOR database,theoretically calculated cross sections using the TALYS and EMPIRE codes,and evaluated nuclear data.

New cross section measurements on tungsten isotopes around 14 MeV neutrons and their excitation functions

New cross sections of the^(183)W(n,α)^(180m)Hf,^(186)W(n,d*)^(185)Ta,^(182)W(n,p)^(182)Ta,^(184)W(n,p)^(184)Ta,^(182)W(n,2n)^(181)W,^(184)W(n,α)^(181)Hf,and^(186)W(n,α)^(183)Hf reactions were measured in the neutron energy range of 13.5-14.8 MeV via the activation technique to improve the database and resolve discrepancies.Monoenergetic neutrons in this energy range were produced via the T(d,n)^(4)He reaction on a solid Ti-T target.The activities of the irradiated monitor foils and samples were measured using a well-calibrated high-resolution HPGe detector.Theoretical calculations of the excitation functions of the seven nuclear reactions mentioned above in the neutron energies from the threshold to 20 MeV were performed using the nuclear theoretical model program TALYS-1.9 to aid new evaluations of cross sections on tungsten isotopes.The experimental data obtained were analyzed and compared with that of previous experiments conducted by other researchers,and with the evaluated data available in the five major evaluated nuclear data libraries of IAEA(namely ENDF/B-VIII.0 or ENDF/B-VII.0,JEFF-3.3,JENDL-4.0u+,CENDL-3.2,and BROND-3.1 or ROSFOND-2010),and the theoretical values acquired using TALYS-1.9 nuclear-reaction modeling tools.The new cross section measurements agree with those of some recent experiments and theoretical excitation curves at the corresponding energies.The consistency of the theoretical excitation curves based on TALYS-1.9 with these experimental data is better than that of the evaluated curves available in the five major nuclear data libraries of IAEA.

Nuclear data for the cyclotron production of ^(117)Sb and ^(90)Nb

This presented study is to make comparison of cross sections to produce 117Sb and 90Nb via different reactions with particle incident energy up to 70 MeV as a part of systematic studies on particle-induced activations on enriched Sn, Y2O3 and ZrO2 targets, theoretical calculation of production yield, calculation of required thickness of target and suggestion of optimum reaction to produce Antimony-117 and Niobium-90.

Cross-sections for(n,2n),(n,α),(n,p),(n,d),and(n,t)reactions on molybdenum isotopes in the neutron energy range of 13 to 15 MeV

Given the insufficient cross-sectional data regarding the 14-MeV-neutron experiment of molybdenum,the vital fusion reactor structural material,and the significant heterogeneities among the reported values,this study examined the(n,2n),(n,α),(n,p),(n,d),and(n,t)reaction cross sections in molybdenum isotopes based on the neutrons produced via a T(d,n)4He reaction carried out in the Pd-300 Neutron Generator at the China Academy of Engineering Physics(CAEP).A high-resolution gamma-ray spectrometer,which was equipped with a coaxial high-purity germanium detector,was used to measure the product nuclear gamma activities.In addition,27Al(n,α)24Na and 93Nb(n,2n)92mNb reactions were utilized as the neutron fluence standards.The experimental 92Mo(n,2n)91Mo,94Mo(n,2n)93mMo,100Mo(n,2n)99Mo,98Mo(n,α)95Zr,100Mo(n,α)97Zr,92Mo(n,p)92mNb,96Mo(n,p)96Nb,97Mo(n,p)97Nb,98Mo(n,p)98mNb,92Mo(n,d)91mNb,and 92Mo(n,t)90Nb reaction cross sections were acquired within the 13-15 MeV neutron energy range.Thereafter,we compared and analyzed these obtained cross sections based on the existing IAEA-EXFOR database-derived experimental data,together with evaluation results corresponding to ENDF/B-Ⅷ.0,JEFF-3.3,BROND-3.1,and CENDL-3.1 and the theoretical outcomes acquired through TALYS-1.95 and EMPIRE-3.2.3(nuclear-reaction modeling tools).

Cross-section measurements of(n,2n)and(n,p)reactions on ^(124,126,128,130,131,132)Xe in the 14 MeV region and theoretical calculations of their excitation functions

The reaction cross-sections of ^(124)Xe(n,2n)^(123)Xe,^(126)Xe(n,2n)^(125)Xe,^(128)Xe(n,2n)^(127)Xe,^(130)Xe(n,2n)^(129)mXe,^(132)Xe(n,2n)^(131)mXe,^(130)Xe(n,p)^(130)I,^(131)Xe(n,p)^(131)I,and ^(132)Xe(n,p)^(132)I were measured at the 13.5,13.8,14.1,14.4,and 14.8 MeV neutron energies.The monoenergetic neutrons were generated via the ^(3)H(d,n)^(4)He reaction at the China Academy of Engineering Physics using the K-400 Neutron Generator with a solid ^(3)H-Ti target.A high-purity germanium detector was employed to measure the activities of the product.The reactions ^(93)Nb(n,2n)^(92m)Nb and ^(27)Al(n,α)^(24)Na were adopted for neutron flux calibration.The cross sections of the(n,2n)and(n,p)reactions of the xenon isotopes were obtained within the 13-15 MeV neutron energy range.These cross-sections were then compared with the IAEA-exchange format(EXFOR)database-derived experimental data,together with the evaluation results of the CENDL-3,ENDF/B-Ⅷ.0,JENDL-4.0,RUSFOND,and JEFF-3.3 data libraries,as well as the theoretical excitation function obtained using the TALYS-1.95 code.The cross-sections of the reactions(except for the ^(124)Xe(n,2n)^(123)Xe and ^(132)Xe(n,p)^(132)I)at 13.5,13.8,and 14.1 MeV are reported for the first time in this study.The obtained results are beneficial in providing better cross-section constraints for the reactions in the 13-15 MeV region,thus improving the quality of the corresponding database.Meanwhile,these data can also be used for the verification of relevant nuclear reaction model parameters.

Measurements of ^(nat) Cd(γ,x)reaction cross sections and isomer ratio of ^(1,5m.g)Cd with the bremsstrahlung end-point energies of 50 and 60 MeV

The flux-weighted average cross sections ^(nat) Cd(γ,xn)^(115g,m,111m,109,107,105,104)Cd and ^(nat) Cd(γ,x)^113g,112,111g,110m)Ag reactions were measured at the bremsstrahlung end-point energies of 50 and 60 MeV.The activa tion and off-line y-ray spectrometric technique was carried out using the 100 MeV electron linear accelerator at the Pohang Accelerator Laboratory,Korea.The ^(nat)lCd(γ,xn) reaction cross sections as a function of photon energy were theoretically calculated using the TALYS-1.95 and the EMPIRE-3.2 Malta codes.Then,the flux-weighted average cross sections were obtained from the theoretical values of mono-energetic photons.These values were compared with the flux-weighted values from the present study and were found to be in general agreement.The measured experimental reaction cross-sections and integral yields were described for cadmium and silver isotopes in the ^(nat)Cd(γ,xn)^(115g,m,111m,109,107,105,104) and ^(nat)Cd(γ,x)^(113g,112.111g,110m)Ag reactions.The isomeric yield ratio(IR) of ^(115g.m)Cd in the ^(nat)Cd(γ,xn) reaction was determined for the two bremsstrahlung end-point energies.The measured isomeric yield ratios of ^(115g,m)Cd in the ^(nat)Cd(γ,xn) reaction were also compared with the theoretical values of the nuclear model codes and previously published literature data of the ^(116)Cd(γ,x) and ^116(γ,2n) reactions.It was found that the IR value increases with increasing projectile energy,which demonstrates the characteristic of excitation energy.However,the higher IR value of ^(115g.m)Cd in the ^(116)Cd(n,2n)reaction compared to that in the ^(116)Cd(γ,x)reaction indicates the role of compound nuclear spin alongside excitation energy.

Measurement of ^(59)Co(ai,x)reaction cross sections with the fast neutrons based on the ^(9)Be(p,n)reaction

The cross sections of the ^(59)Co(n,x)reaction in the average energy range of 15.2-37.2 MeV were meas-ured using activation and an off-line γ-ray spectrometric technique.The neutrons were generated from the ^(9)Be(p,n)reaction with proton beam energies of 25-45 MeV at the MC-50 Cyclotron facility of the Korean Institute of Radi-ological and Medical Sciences(KIRAMS).Theoretical cal lculations of neutron-induced reactions on ^(59)Co were per-formed using the nuclear model code TALYS-1.9.The results for the ^(59)Co(n,x)reactions were compared with the theoretical values obtained using TALYS-1.9 and the literature data provided in EXFOR and the TENDL 2019 nuc-lear data library.The theoretical values obtained using TALYS-1.9 with adjusted parameters are comparable to the experimental data.The measured reaction cross sections of a few radionuclides are new,and the others are compar-able to the literature data,and thus,they can strengthen the database.The present study on cross sections leads to useful insight into the mechanisms of ^(59)Co(n,x)reactions.

Measurement of(n,α)and(n,2n)reaction cross sections at a neutron energy of 14.92±0.02 MeV for potassium and copper with uncertainty propagation

Experimentally measured neutron activation cross sections are presented for the ^(65)Cu(n,0)^(62m)Cu,^(41) K(n,a)^(38C)l,and ^(65)Cu(n.2n)^(64)Cu reactions with detailed uncertainty propagation.The neutron cross secions were measured at an incident energy of 14.92±0.02 MeV,and the neutrons were based on the(d,n)a fusion reaction.The ^(27) Al(n,a)^(24)Na reaction was used as a reference reaction for the normalization of the neutron flux.The pre-calib-rated lead-shielded HPGe detector was used to detect the residues'γ-ray spetra.The data from the measured cross sections are compared to the previously measured cross sections from the EXFOR database,theoretically calculated cross sections using the TALYS and EMPIRE codes,and evaluated nuclear data.