Parameters of <Emphasis Type="Italic">s</Emphasis>-resonances in <Superscript>246–248</Superscript>Cm fission cross sections

The fission cross sections of ²⁴⁶Cm, ²⁴⁷Cm, and ²⁴⁸Cm isotopes measured with an SVZ-100 spectrometer, based on neutron moderation in lead, at the Institute of Nuclear Research of the Russian Academy of Sciences are analyzed. The area of the resolved resonances is calculated, and their neutron and fission widths are determined. The results are compared with existing data and recommended evaluations.     

Experimental determination of <Superscript>80,82,83</Superscript>Kr(α, <Emphasis Type="Italic">xn</Emphasis>)<Superscript>82</Superscript>Sr cross sections for reaction threshold to 60 MeV α-particles

The activation method has been used to determine the experimental cross sections of the nuclear reactions ⁸⁰Kr(α, 2n)⁸²Sr, ⁸²Kr(α, 4n)⁸²Sr, and ⁸³Kr(α, 5n)⁸²Sr for α-particle energies from the reaction threshold to E_α = 60 MeV on targets which are highly enriched with krypton isotopes. The structural and geometric parameters are established for a “thick” cascade target with krypton isotopes, which gives maximum ⁸²Sr yield for E_α ≤ 60 MeV. The ⁸²Sr yield in the indicated target for initial energy E_α = 60 MeV is estimated to be 3.4·10⁶ Bq/(μA·h), which gives a basis for commercial applications of this isotope in medium-energy accelerators.     

Cosmogenic <Superscript>7</Superscript>Be fallout near Samarkand in 2002–2009

⁷Be fallout measurements performed around Samarkand in 2002–2009 are presented. The calendar period included in this research covers the ascending part of the 23rd solar activity cycle; this part of the cycle corresponded to a decrease of the monthly average value of the Wolf number from 60 to <5. The linear correlation observed between the fallout and amount of wet precipitation indicates that the latter plays the main role in the removal of ⁷Be from the troposphere. The average seasonal ⁷Be fallout is 223 ± 46 Bq/m² during winter, 324 ± 66 Bq/m² during spring, 75 ± 29 Bq/m² during summer, and 189 ± 43 Bq/m² during fall. These measurements make it possible to evaluate the contribution of precipitation in the form of dust and dew to the total ⁷Be fallout during the summer. The correlation between the solar radiation and ⁷Be fallout is confirmed.     

俄罗斯与IAEA共建"核燃料银行"

[世界新闻报2010年12月17日报道]俄罗斯国家原子能公司(Rosatom)于2010年12月1日发布公告称,俄罗斯与国际原子能机构(IAEA)共同建设的全球首家用于储备低浓铀的核燃料银行将位于西伯利亚     

乏燃料后处理厂"红油"爆炸安全分析

介绍了乏燃料后处理厂不稳定化合物"红油"(采用的萃取剂磷酸三丁脂TBP和稀释剂及其它们的降解产物与来自硝酸或相关重金属铀或钚的硝酸盐之间的反应)的形成及其引发的爆炸机理,简要概述了在世界范围内后处理厂发生的重要的相关爆炸事件或事故,对具有代表性的高放废液蒸发器发生这类事故进行了后果评价,并阐明了后处理厂为避免"红油"爆...     

<Superscript>246–248</Superscript>Cm Neutron fission cross sections and resonance integrals

The fission cross sections of ^246–248Cm nuclei for neutron energies 0.1 eV–20 keV have been measured using an SVZ-100 lead moderation time neutron spectrometer at the Institute of Nuclear Research of the Russian Academy of Sciences. The fission resonance integrals have been calculated. The results are compared with the existing data and recommended evaluations.     

Pre-Equilibrium <Superscript>3</Superscript>He-Emission Spectra at 62 MeV Proton Incident Energy

In this study, the ³He-emission cross sections for ²⁷Al, ^54,56Fe, ¹⁹⁷Au, ²⁰⁸Pb and ²⁰⁹Bi target nuclei have been calculated at 62 MeV proton energy. In these calculations, the pre-equilibrium effects have been investigated. The pre-equilibrium calculations involve the geometry dependent hybrid model and hybrid model. A comparison with theoretical calculations (ALICE/ASH) has been performed and the empirical formulas for the ³He- emission cross sections produced at 62 MeV proton energy have been derived.     

俄新航母杀手"亚森"级核潜艇下水

[美国《战略之页》网站2011年2月27日报道]俄罗斯亚森级(北约称之为葛兰尼级)攻击型核潜艇已正式下水,并开始海上测试.由于性能先进且装备有威力强大的导弹武器,亚森将成为俄海军新一代航母杀手.如果一对一单挑,俄罗斯的这款核潜艇敢跟任何一个对手叫板.报道称,由于缺少经费,亚森级核潜艇的建造进程被一拖再拖.早在5年前,     

β-γ符合效率外推法绝对测量133Xe活度

放射性气体氙监测是全面禁止核试验条约国际监测系统关注的重点之一,准确测量放射性气体氙活度是其中的难点。本文详细介绍了β-γ符合效率外推法测量放射性核素活度的原理和方法,并绝对测量了¹³³Xe活度。结果表明,β-γ符合效率外推法作为一准确度较高的放射性核素活度绝对测量方法,可应用于气体放射性核素的活度测量;为提高测量准确度,可通过减小气体自吸收效应提高β探测效率。     

富集中间组分同位素的级联—— “T”级联

除了常规矩形级联和阶梯级联等模型外，还有一些其他的级联模型，使用这些特殊级联可以达到特殊分离目的。本文提出一种用于中间组分同位素分离的特殊级联“T”级联。该级联模型可以通过一点供料三点取料的模式，直接提取中间组分同位素。以氙同位素为例，进行理论计算，“T”级联可以一遍分离直接获取丰度90%以上的¹³¹Xe同位素，略高于双级联分离能力。结果表明，“T”级联适合进行中间组分同位素的一遍提取分离。     

英国皇家海军命名第五艘"机敏"级核潜艇

[德国国防专业网站2011年9月16日报道]英国海军近日将其最新的一艘机敏级潜艇正式命名为安森(Anson).安森是第5艘机敏级潜艇,以因环球航行和在七年战争中领导英国海军而闻名的海军上将乔治?安森(1697-1762年)的名字命名.国防大臣Liam Fox博士称:我很高兴     

惰性气体氙β-γ符合能谱分析软件的研制

基于惰性气体氙β-γ符合测量原理,研究建立了基于相关法的符合谱解谱算法,研制了具有图形化用户界面的惰性气体氙β-γ符合能谱分析软件,实现了β-γ符合能谱的分析、能谱的图形化显示和分析结果数据库存储等功能,使北京放射性核素实验室具备了惰性气体氙β-γ符合能谱数据的分析处理能力。并与国际数据中心的β-γ符合能谱自动处理程序bg_analyze进行了比较,结果表明：两种软件的4种氙同位素活度浓度计算结果在1.2%内一致;最小可探测浓度计算结果在1.7%内一致。     

Calculation of Cross-sections and Astrophysical S-Factors for <Superscript>62</Superscript>Ni(α,n) and <Superscript>62</Superscript>Ni(α,γ) Reactions of Structural Fusion Material Nickel

Nickel is an important element in fusion reactor technologies and astrophysical applications. Therefore, the knowledge of astrophysical S-factors and cross-sections on nickel isotopes is needed. In this work, the cross sections of the ⁶²Ni(α,n) and ⁶²Ni(α,γ) reactions have been calculated. The alpha capture cross sections was calculated up to 10 MeV. In these theoretical calculations, the TALYS 1.6 and NON-SMOKER codes were used. Also for the ⁶²Ni(α,n) and ⁶²Ni(α,γ) reactions, we calculated the astrophysical S-factors that determine the probability of reaction in low energies. Results of our calculations were checked to the experimental data obtained from EXFOR database.     

Interaction of 〈1 0 0〉 and ½〈1 1 1〉 dislocation loops with point defects in ferritic alloys

The interaction between dislocation loops of interstitial nature with ½〈1 1 1〉 and 〈1 0 0〉 Burgers vectors and point defects in Fe has been studied molecular dynamics. Comparative calculations have been carried out using two interatomic potentials for pure Fe ([G.J. Ackland, M.I. Mendelev, D.J. Srolovitz, S. Han, A.V. Barashev, J. Phys.: Condens. Mater. 16 (2004) 1; S. Dudarev, P. Derlet, J. Phys.: Condens. Mater. 17 (2005) 7097]). The results of this study are range and energy of the interaction as functions of size and mutual position of defects. The applied potentials predict somewhat different strain field structure for 〈1 0 0〉 loops and therefore different lengths of interaction. However, both potentials suggest that, contrary to common belief, the distance of cluster-defect interaction within the glide prism of a ½〈1 1 1〉 cluster is significantly longer than that of a 〈1 0 0〉 cluster of similar size, in spite of the longer Burgers vector in the latter case.     

美国铀浓缩公司与投资方达成"暂停投资协议"

[世界核新闻网站2011年7月1日报道]由于无法在2010年商定的最终期限之前获得由美国政府提供的贷款担保,美国铀浓缩公司(USEC)近日与其投资方日本东芝公司(Toshiba)及美国巴布科克·威尔科克斯公司(B&W)达成一项暂停投资协议.     

俄罗斯没有让"台风"级潜艇退役的计划

[俄罗斯国际新闻通讯社莫斯科2011年9月30日电]俄罗斯国防部一名高官在9月29日接受俄新社采访时否认了台风级潜艇将于近期退役的传言.此前曾有多家媒体报道俄罗斯国防部决定到2014年退役这种世界上最大的核潜艇.国防部没有做出这样的决定.该级潜艇仍在海军服役.这名高官称.第一艘台风级核潜艇(TK-208号)于1977年...     

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应用中子衍射方法和Rietveld法全谱图拟合，研究了微晶玻璃在缓冷和急冷两种热处理条件下微结构和内应力的变化。与缓冷处理相比，急冷处理使析出的β硅灰石晶体的晶胞沿着3个晶轴方向进一步拉伸，晶体受到残余非晶相的拉应力作用更大，但原子位置无序相对要小，过高的局部应力导致了应力集中区内微裂纹的出现。急冷处理样品在高角度处的非晶峰强度远高于缓冷处理样品，表明急冷处理样品中残余玻璃相的比例更高。中子衍射获得的应变值与X射线衍射结果有显著差别，显示材料体内应力和表面应力有很大不同。中子衍射是测定大块微晶玻璃试样的平均残余应变和研究其复杂的两相共存结构的一种可行方法。