Determination of differential cross-sections for the natK(p, p0) and 39K(p, α0) reactions in the backscattering geometry

In the present work, new, differential cross-section values are presented for the ^natK(p, p₀) reaction in the energy range E_lab = 3000–5000 keV (with an energy step of 25 keV) and for detector angles between 140° and 170° (with an angular step of 10°). A qualitative discussion of the observed cross-section variations through the influence of strong, closely spaced resonances in the p + ³⁹K system is also presented. Information has also been extracted concerning the ³⁹K(p,α₀) reaction for E_lab = 4000–5000 keV in the same angular range. As a result, more than ～500 data points will soon be available to the scientific community through IBANDL (Ion Beam Analysis Nuclear Data Library – http://www-nds.iaea.org/ibandl/) and could thus be incorporated in widely used IBA algorithms (e.g. SIMNRA, WINDF, etc.) for potassium depth profiling at relatively high proton beam energies.     

Excitation Functions for the Reactions Ti(α,x)~(51)Cr and Ti(α,x)~(48)Cr

Introduction The excitation function measurement of charged-particle-induced nuclear reaction is an useful subject for reasons of both basic knowledge and technological progress. It is important in such fields as production of radio-isotopes with an accelerator, charged-particle activation analysis, thin-layer activation for study of wear and erosion in a metal and research of nuclear reaction mechanism, etc.     

~(56)Fe(d,x)反应的截面

５６Ｆｅ（ｄ，ｘ）反应的截面许晓萍韩银录庄友祥（中国原子能科学研究院）关键词５６Ｆｅ带电粒子核数据氘核光学势参数能级密度参数５６Ｆｅ氘核反应的截面在核科学与工程中有着重要应用，而其实验数据比较少，有必要对此进行可靠的理论计算，预言一些无实验数据的反应...     

Measurement of thermal neutron capture cross section and resonance integral of the 138Ba(n, γ)139Ba reaction using 55Mn(n, γ)56Mn as a monitor

The thermal neutron capture cross section (σ_o) and the resonance integral cross section (I_o) of the ¹³⁸Ba(n, γ)¹³⁹Ba reaction have been measured by the activation method using the Ghana Research Reactor-1 (GHARR-1). The barium and manganese targets were irradiated within and without a cadmium capsule. The result of the thermal neutron capture cross section for the ¹³⁸Ba(n, γ)¹³⁹Ba reaction is 0.53 ± 0.01barns. The result was obtained relative to the reference value 13.2 barns of the ⁵⁵Mn(n, γ)⁵⁶Mn reaction. The resonance integral cross section for the ¹³⁸Ba(n, γ)¹³⁹Ba reaction was also measured relative to the reference value of 13.9 barns for the ⁵⁵Mn(n, γ)⁵⁶Mn reaction. The present resonance integral cross section for the ¹³⁸Ba(n, γ)¹³⁹Ba reaction is 0.380 ± 0.005 barns. The previous measurements of the σ_o and I_o of the reaction ¹³⁸Ba(n, γ)¹³⁹Ba were reviewed and the difference between the present values and the previous results were discussed. The present work was undertaken with the aim to contribute to the experimental basis of σ_o and I_o evaluations.     

Evaluation of Neutron Monitor Cross Sections for ~(59)Co(n,x)~(56, 57, 58)Co,~(52, 54, 56)Mn,~(59)Fe Reactions

The neutron monitor cross sections for ~(59)Co(n,x)~(56, 57, 58)Co,~(52, 54, 56)Mn,~(59)Fe reactions were evaluated based on recent experimental data and theoretical cal culations from threshold energy to 100 MeV.     

A novel (SiC)1−x(AlN)x compound synthesized using ion beams

The formation of a novel (SiC)_1−x(AlN)_x compound (x=0.2) at low temperatures within the miscibility gap of the SiC/AlN phase diagram by hot, high-dose co-implantation of N⁺ and Al⁺ ions into 6H–SiC substrates is investigated. The compound layers have been studied by Rutherford backscattering spectrometry/ion channelling (RBS/C), Auger electron spectroscopy (AES), polarized infrared reflection spectroscopy (PIRR) and cross sectional electron microscopy (XTEM) and the temperature dependence of their fabrication has been examined. An optimum temperature window has been established within which the structure of the synthesized material retains good crystallinity during implantation.     

共沉淀法制备(Th,U)O_(2+x)粉末工艺研究

采用共沉淀工艺制得钍铀共沉淀物(AUTh C),AUTh C经分解还原得到(Th,U)O2+x粉末。采用差热-热重分析仪分析AUTh C分解过程,多分子层吸附理论(BET)法测定(Th,U)O2+x粉末比表面积。研究p H值、氨水加入量等共沉淀反应条件对钍铀共沉淀反应影响,以及无水乙醇处理AUTh C对(Th,U)O2+x粉末比表面积影响。实验结果表明:缓慢加入碳酸铵使p H值为5.5时,钍铀均具有较高沉淀率。加入氨水使p H升至7.5以上时,能明显提高钍铀共沉淀性能,母液中残余铀浓度为89 mg/L,残余钍浓度为105 mg/L。使用无水乙醇处理AUTh C能防止分解过程中(Th,U)O2+x粉末出现硬团聚;分解终点温度为600℃下保温2 h,(Th,U)O2+x粉末比表面积达15 m2/g。     

Evaluation of Cross Sections for Neutron Monitor Reactions ~(54,56,Nat)Fe(n,x)~(51)Cr,~(52,54)Mn

Introduction Iron is a very important structure material in nuclear engineering. Meanwhile, knowledge of the neutron monitor reactions for natural iron and its isotopes has been used for the evaluation of radiation induced material damage, radiation safety, neutron dosimetry, etc..     

中子散射研究HoFe_(1-x)Cr_xO_3(x=0.0,0.2,…,1.0)固溶体磁性

正利用固相反应法制备了HoFe_(1-x)Cr_xO_3(x=0.0,0.2,…,1.0)系列固溶体化合物,利用磁性测量和变温中子衍射对样品进行了研究,建立了体系的磁相图。发现随着Cr从0.0到1.0,体系的Neel温度大约从650K下降到140K。在x=0.0～0.7的范围之内,在Neel温度以下体系呈现Γ4反铁磁结构,在某一温度T_(sr)下,体系磁结构转变为Γ_2结构。随着x从0.0增加到0.7,T_(sr)逐渐从56 K增加到大于200 K并接近T_N。当x处于0.8～1.0之间的时候,在T_N以下系统     

The Comparison of (n,p), (n,α), (n,2n) and (α,n) Reaction Cross-Sections for <Superscript>7</Superscript>Li and <Superscript>9</Superscript>Be Target Nuclei

The knowledge of the cross-section is important especially for the fusion and fission reactor technology. In the absence of experimental data or in the difficulty of measuring data, theoretical predictions of nuclear cross-section data are needed to be improved using model calculations or semi-empirical formulas and to be compared with model and formulas to obtain sensitive approaches. In this work, for ⁷Li and ⁹Be target nuclei used as blanket materials in fusion reactors, (n,p), (n,α), (n,2n) and (α,n) reaction cross-section data have been evaluated by using some available empirical and semi-empirical cross-section formulas. The (n,p), (n,α), (n,2n) and (α,n) reaction cross-section formulas developed for medium and heavy mass nuclei by some scientist in literature are applied to ⁷Li and ⁹Be light nuclei and then results obtained from any systematics are compared with each other and the existing experimental data.     

The Calculations of ~(56)Fe(n,x)~(51)Cr,~(52,54,56)Mn Reactions Cross Sections up to 60 MeV

A set of neutron optical potential parameters for ~(56)Fe in energies of 4～100 MeV was obtained by fitting available experimental data. The yield cross sections of the activation isotopes ~(51)Cr, ~(52)Mn, ~(54)Mn, and ~(56)Mn in n ~(56)Fe reaction are calculated and predicted in energy range up to 60 MeV.     

A study on the excitation functions of ~(60,62)Ni(α,n),~(60,61)Ni(α,2n),~(58,64)Ni(α,p),~(nat)Ni(α,x) reactions

The prediction of nuclear cross-section data is crucial, especially in the absence of experimental data or in the difficulty of these experimental data. Nickel(Ni) is an important material in fusion and fission reactor technologies, the production of radionuclides in nuclear medicine,and many other fields. In this study, the excitation functions for~(60,62) Ni(a,n),~(60,61) Ni(a,2 n),~(58,64) Ni(a,p), and ~(nat)Ni(a,x) reactions have been investigated by using preequilibrium reaction models. The calculations of the excitation functions for the reactions are used with the geometry-dependent hybrid model in ALICE/ASH code and the two-component exciton model in TALYS 1.8 code. The obtained results are compared to each other, and the experimental data are taken from the EXFOR database.     

Measurements of activation cross sections for Lu(n, α)Tm,Lu(n, α)Tm and Lu(n, p)Yb reactions induced by neutrons around 14 MeV

The cross sections for the ¹⁷⁵Lu(n, α)¹⁷²Tm, ¹⁷⁶Lu(n, α)¹⁷³Tm and ¹⁷⁵Lu(n, p)^175m+gYb reactions have been measured in the neutron energy range of 13.5–14.8 MeV using the activation technique. The first data for ¹⁷⁵Lu(n, α)¹⁷²Tm reaction cross sections are presented. In our experiment, the fast neutrons were produced via the ³H(d, n)⁴He reaction on K-400 Neutron Generator at Chinese Academy of Engineering Physics (CAEP). Induced gamma activities were measured by a high-resolution (1.69 keV at 1332 keV for ⁶⁰Co) gamma-ray spectrometer with high-purity germanium (HPGe) detector. Measurements were corrected for gamma-ray attenuations, random coincidence (pile-up), dead time and fluctuation of neutron flux. The neutron fluences were determined by the cross section of ⁹³Nb(n, 2n)^92mNb or ²⁷Al(n, α)²⁴Na reactions. The neutron energy in the measurement was by the cross section ratios of ⁹⁰Zr(n, 2n)^89m+gZr and ⁹³Nb(n, 2n)^92mNb reactions. The results were discussed and compared with experimental data found in the literature and with results of published empirical formulae.     

Neutron Scattering Study of Magnetism of HoFe_(1-x)Cr_xO_3(x=0.0,0.2,…,1.0) Solid Solutions

<正>The solid solutions HoFe_(1-x)Cr_xO_3(x=0.0,0.2,…,1.0)have been synthesized by solid reaction method,and investigated by both magnetometry and neutron powder diffraction.A magnetic phase diagram was established.With Cr-composition increase from 0.0 to 1.0,the system’s Neel temperature decreases from 650K     

The Evaluation and Calculation of Production Cross Sections for ~(11)C, ~(13)N and ~(15)O from ~(11)B, ~(13)C, ~(15)N(p,n) and ~(16)O(p,x)~(13)N Reactions up to 80 MeV

Introduction The medical radioisotopes are used for diagnostic and therapeutic purposes, as well as metabolism and physiological function researches in modern medicine. If a short-lived radioisotope emits a predominant or single γ-rays of 60～300 keV, it is of greater advantage since single photon emission computed tomograph(SPECT) can be performed; similarly β~ emitters are also of great significance since three dimensional high resolution scans can be obtained via     

Evaluation and Calculation of Activation Cross Sections for ~(151,153)Eu(n,2n), (n,3n), (n,γ) and (n,x) Reactions below 20 MeV

Eu is a rare-earth element. Its activation cross section is important for nuclear science and technology applications. However, there are some discrepancies in several evaluated nuclear data libraries. The cross section for ~(151,153)Eu(n,2n) reactions were one of the Coordinate Research Programs of IAEA on activation cross sections     

Evaluation of Cross Sections for Neutron Monitor Reactions ~(90)Zr(n,x)~(89,88)Zr,~(88,87,86)Y from Threshold to 100 MeV

The cross sections for ~(90)Zr(n,x)~(89,88)Zr and ~(90)Zr(n,x)~(88,87,86)Y reactions in intermediate energy region are useful in neutron field monitor, safety and material damage research. Below 20 MeV, the evaluated cross sections for (90)Zr(n,2n)~(89)Zr reaction are recommended based on the recent experimental data, including the new measured results in CIAE(Above 20 MeV). The measured cross sections are still insufficient to do evaluation. So the evaluation for ~(90)Zr(n,x)~(89,88)Zr and (90)Zr(n,x)~(88,87,86)Y reactions from threshold to 100 MeV are based on experimental and calculated data.     

基于GeTHU测量确定natPb(p,x)207Bi和natPb(p,x)194Hg的反应截面

加速器驱动次临界系统(Accelerator Driven Sub-critical System,ADS)是最具潜力的下一代核能系统选型之一，准确评估ADS散裂靶内产生的长寿命放射性核素含量是应用研究中的重要课题，利用质子活化法可以有效评价质子与散裂靶材料发生相互作用产生长寿命核素的反应截面。4个质子辐照天然铅样品分别被能量为40 MeV、70 MeV、100 MeV和400 MeV的质子照射90 min、75 min、40 min和25 min，在冷却约20 a后，利用中国锦屏地下实验室(China Jinping Underground Laboratory,CJPL)的超低本底γ谱仪GeTHU进行测量，使用SAGE(Simulation and Analysis for Germanium Experiments)模拟框架计算了GeTHU的探测效率，测定了能量为40 MeV、70 MeV、100 MeV和400 MeV质子与天然铅发生^natPb(p,x)²⁰⁷Bi和^natPb(p,x)¹⁹⁴...     

Progress on Measurement of (n,x) Cross Sections at HST in 1995

1 The Measurement of Energy Spectrum and Angular Distributions of Protons Emission from Reaction induced by 14.6 MeV Neutron Bombarding Stainless Steel This experiment has been performed at Univ. of Sci. and Tech. of China,Hefei(HST) by using multitelescope system. 14.6 MeV neutrons were produced by 150 kev Cockcroft-Walton accelerator. The 1Cr 18Ni 9Ti(type 321)stainless steel target with 0.8 mm thick and 40 mm height was used. The elemental composition of type 321 stainless steel is given in Table 1.