~(197)Au(γ，n)的反应截面的测量

正光中子核反应~(197)Au(γ,n)196 Au的反应截面在前人的实验中已测得了大量数据,它通常被认为是研究光核反应的1个标准反应而进行比对。前人基于多种γ源对~(197)Au(γ,n)~(196)Au的反应截面进行了测量。1987年,Berman等利用飞行正电子湮灭γ源对~(197)Au等核素进行了光核反     

EVALUATION OF ~(197)Au(n,2n)~(196)Au REACTION CROSS SECTION

~(197)Au(n,2n)~(196)An cross section is one of the important dosimetry reactioncross sections.Since the fifties more than 30 measurements have been completed and the evaluation works have also been reported from time to time.It isnoted that most of the measured data published in the eighties are more or lesslower than the existed evaluated data,and some of the newly measured data     

基于~3He球的(n,2n)反应截面测量技术

正中国原子能科学研究院核数据重点实验室原来的~(3)He球探测系统包含有80根~(3)He管,为了进一步提升系统对中子的探测效率,增加了30根~(3)He管。升级后的探测系统共有110根~(3)He管。该系统中子离线探测效率用~(252)Cf自发裂变源进行了标定,总效率值可达(29±2)%。这套     

~(89)Y(n,2n)~(88)Y反应截面测量

利用活化法的基本原理和相对测量方法,测量得到13.5～14.8MeV的D-T中子作用下的89Y(n,2n)88Y反应截面。89Y(n,2n)88Y反应截面为629～1053mb,相对不确定度为1.7%。并与采用大液闪测量的实验结果和ENDF/B-6库的截面数据进行了比较,当中子能量为14.1MeV处ENDF/B-6数据与实验值的比值为0.99。     

~(176)Hf(n,2n)~(175)Hf反应截面测量

采用相对测量技术,以活化法对13.4～14.8MeV范围内的176Hf(n,2n)175Hf反应截面进行了测量。样品固定在距离D-T中子源20cm处的圆环的不同位置上进行中子辐照,采用93Nb(n,2n)92Nbm作为监测反应,活化产物采用高纯锗探测器进行了测量,所得14MeV附近的176Hf(n,2n)175Hf反应截面实验值为(2100±85)mb,对实验结果与公开文献值和ENDF/B6.8评价库数据进行了比对。     

Evaluation of Cross Sections for ~(197)Au(n,3n) and ~(197)Au(n,4n) Reactions from Threshold to 50 MeV

The measured data of cross sections for ~(197)Au(n,3n) and ~(197)Au(n,4n) reactions were collected and analysed. The theoretical calculations of above mentioned reactions were carried out to predict the data in higher energy region. The sets of cross sections for ~(197)Au(n,3n) and ~(197)Au(n,4n) reactions from threshold to 50 MeV were recommended on the basis of the experimental and calculated data.     

The Cross Section Evaluation and Recommendation of ~(197)Au (n,2n)~(196)Au Reaction

The evaluation for 197Au(n,2n)196Au cross section was performed, the data of this reaction in the neutron energy range from threshold to 30 MeV were given, compared with the evaluation results by YUAN Hanrong et al., ZHAO Wenrong et al, Jose Martinez-Rico and YU Baosheng et al.. The agreement between different evaluations is good. However, the deviations are shown up for the data from ENDF/B-6 and JEF-2.2.     

用于(n,2n)反应截面测量的~3He球中子探测器阵列研制

正在(n,2n)反应截面测量中,通常使用活化法,该方法的优点是简单,在产物核满足一定条件的情况下,可以达到高精度测量。但当产物核无法进行活度的精确测量时,该方法就不适用,为弥补活化法的不足,本工作设计研发了一套3 He球中子探测器阵列(图1),用于直接测量(n,2n)反应发出的两个中子,从而实现(n,2n)反应截面测量的目的。该探测器阵列由110根3 He管和聚乙烯球慢化体组成,采用波形数字化数据获取系统,实现每个时间的时间和能量测量。该系统对252 Cf源的探测效率约33%。     

Measurement of Isomer Cross Section for the ~(197)Au(n,2n)~(196m2)Au Reaction at around 14 MeV

The intensity of196m2Au 148 keV γ-ray and time relation of intensity of 1968Au 356 keV γ-ray were measured with a HPGe detector. The cross section of 197Au(n,2n)196m2Au was obtained to be 182±15mb, by two methods with DT neutrons.     

~(154)Sm(n,2n)~(153)Sm和~(148)Sm(n,p)~(148)Pm反应截面的测量

报道了在Ｅｎ＝１４．５－１４．９ＭｅＶ中子能区用活化法以２７Ａｌ（ｎ，α）１４Ｎａ的反应截面为中子注量标准测得的１５４Ｓｍ（ｎ，２ｎ）１５３Ｓｍ和１４８Ｓｍ（ｎ，ｐ）１４８ｇＰｍ反应截面，并将其与已有的数据进行了比较。中子能量用铌锆截面比法测定。     

~(141)Pr(n,γ)~(142)Pr反应截面的测量

用活化法测量了中子能量在 0.539 MeV,1.090 MeV 和 1.587MeV 的 Pr(n, γ)142Pr 核反应截面值,γ 放射性活度用高纯锗探测 141器测量,实验的测量误差在±(6～7)%范围内。实验结果与其它各家的实验值进行了比较和分析,给出了推荐的激发曲线。     

~(56)Fe(n,p)~(56)Mn反应截面的测量

在E_n=12.8—18.2兆电子伏能区,用活化法测量了~(56)Fe(n,p)~(56)Mn反应截面,在E_n=14.63±0.20兆电子伏处做了绝对测量,结果为108.0±2.9毫靶。中子通量用伴随粒子法测定。对T(d,n)~4He反应的中子角分布也作了测定。~(56)Mn的放射性用φ10×7.6厘米的Nal(Tl)闪烁谱仪测量,~(56)Mn特征γ射线的探测效率用4πβ-γ符合法测定的~(56)Mn标准源刻度。本文还对用伴随粒子法测量中子通量作了较详细的叙述。测量结果同国外数据作了比较,并做了简短讨论。     

Evaluation of Neutron Monitor Cross Section for ~(197)Au(n,2n)~(196)Au Reaction from Threshold to 80 MeV

The evaluation of intermediate energy nuclear data for the ~(197)Au(n,2n)~196 Au reaction cross section is very important to monitor high energy neutron field, neutron activation, dosimetry and radiation induced material damage etc.. This work was undertaken to provide more precise and complete interme     

实验测定~(116)Cd(n,2n)和~(115)In(n,p)反应截面

一、引言由于对~_(116)Cd(n,2n)反应的截面测量数据分歧较大,而关于~(115)In(n,p)反应,文献中也只报导了该反应的总截面,对亚稳态和基态的截面国内外报导得均很少,因此,我们通过实验来测定~(116)Cd(n,2n)和~(115)In(n,p)反应中产生的~(115m,g)Cd的截面和它们     

中子活化法测量238U(n,2n)反应截面

利用PD-300加速器提供的D-T聚变中子,采用中子活化法测量了238U(n,2n)反应截面;中子能量监测采用93Nb(n,2n)92m Nb和90Zr(n,2n)89m+gZr截面比法,中子通量监测利用238 U自身反应道238U(n,f);通过测量237U发射的208 keV的γ射线,得到了 13～15 MeV能区...     

~3He(d,p)~4He反应截面的测量

本工作对~3He(d,p)~4He反应在实验室系90°角进行了激发函数的测量。入射氘的能量为200千电子伏到1000千电子伏。在激发函数的共振峰上(E_d=420千电子伏),测量了微分截面绝对值。利用此反应在低入射能量情况下角分布为各向同性的特点,推得了全截面为847±53毫靶。将此实验结果和前人的工作结果进行了比较。     

~(182)W(n,n′α)~(178)Hf~(m2)反应截面研究

对当前有关182W(n,n′α)178Hfm2反应截面的实验测量值和理论计算值相差100倍这一分歧进行了样品成分活化分析和仔细的理论分析。所得结果排除了实验所用样品存在Hf杂质影响这一推论。理论和实验值的分歧依然存在,可能原因是现有的理论计算程序还不能对高角动量激发态进行很好的理论预言     

Cross Section Measurements for ~(199)Hg(n,p)~(199)Au,~(198)Hg(n,p)~(198)Au,~(196)Hg(n,p)~(196)Au and ~(196)Hg(n,d np pn)~(195)Au Reactions

Introduction The importance of nuclear data for fusion power reactor design has been acknowledged, in particular for safety, environment reasons and economics. The 14 MeV neutron activation cross sections are the key nuclear data for environmental impact, material recycling, waste handling. Due to the large     

Dynamic Study on Damped Reactions of ~(244)Pu ~(244)Pu,~(238)U ~(238)U and ~(197)Au ~(197)Au

In most attempts to produce superheavy elements(SHE), the complete fusion reactions have successfully been tried. Since the 70’s the elements from Z=107 to 116 were synthesized in the “cold fusion” reactions with lead and bismuth targets and “hot fusi…