POSITRON LIFETIME STUDIES ON SYSTEMS OF PALLADIUM FILLED GALVANOSTATICALLY WITH HYDROGEN OR DEUTERIUM

The positron lifetime spectroscopy was used to investigate the electron structures of crystal lattice and its defects in palladium samples filled galvanostatically with hydrogen and deuterium, respectively. The results have indicated that the positron lifetime were all the same between hydrogen and deuterium filled samples in which the positron lifetime τ(?) increased about 10%, corresponding to the volume expansibility after the formation of hydrides PdH or PdD phases during electrolyzing commom water or heavy water with Pd cathode; and Will not change with time in 3 weeks after stopping electrolysis; but could be recovered to 116±1ps, the value in polycrystalline pure palladium, after annealing at high temperature.     

RADIATION EFFECT OF HOME-MADE STAINLESS STEEL STUDIED BY POSITRON ANNIHILATION

The heavy ion irradiation is used for the first time to simulate the radiation damage produced by reactor neutrons in home-made modified stainless steels. The produced radiation damage is investigated by the positron annihilation spectroscopy. No detectable radiation damage is observed in the home-made modified stainless steels irradiated by 81.6 MeV carbon ions to a total dose of 3.3×1016 cm-2 , indicating that the home-made modified stainless steel of this type has good radiation resistant properties.     

A PRELIMINARY STUDY OF EMBRITTLEMENT OF Co-BASED AMORPHOUS ALLOYS BY POSITRON ANNIHILATION

Measurements of the Doppler broadening S-lineshape parameter of positron annihilation and brittleness have been performed for two Co-based amorphous alloy prior to crystallization. It is shown that the brittleness is related to the S-parameter, that is, microdefects may be one of the important factors affecting the embrittlement of the Co-based amorphous alloys.     

用γ谱仪测定高温焚烧炉炉渣中的放射性核素

一、引言 高温焚烧炉是一种处理中低放固体废物的装置,它可将废物中的绝大部分放射性核素安全地包容于颗粒状的炉渣之中。这种炉渣的主要成份是氧化硅和氧化铁。对炉渣中放射性核素的测定可用常规的放化方法来实现,即破碎、溶解、分离及最后的放射性测量。显然,这是十分烦杂的,而非破坏性的直接测量无疑要简单得多。射线通过物质时由于吸收作用而衰减。虽然γ射线有较强的穿透能力,它毕竟要在某种程度上为物质所吸收。非破坏测量的     

小型高分辨率^3He／^4He质谱计的离子光学

一、前言地球上氦同位素组成有三个层次:地幔氦、地壳氦和大气氦。地幔氦是地球生成时保留下来的原生氦,~3He含量高,~3He/~4He比值约10~(-5);地壳氦是地壳中铀、钍等放射性元素蜕变过程中生成的,~3He/~4He比值约10~(-7)～10~(-8);大气氦是在地幔氦与地壳氦不断地向     

用飞行时间法鉴别粒子的在线三体谱仪的改进

针对迴旋加速器加速相位的不稳定,研制了频率自动微调系统,并用靶上二体事件单能粒子的时间线谱作监控修复信号,减小了迴旋加速器等系统的不稳定而带来的时间幌动,将迴旋加速器上谱仪鉴别粒子的时间分辨降低到<3ns。     

慢正电子束研究电子束固化涂层的微观结构

用慢正电子束多普勒展宽谱研究环氧丙烯酸酯体系电子束固化涂层。Ｓ－Ｅ曲线给出了稀释剂分子结构及其相对含量，辐射剂量，预聚物和交联剂含量等对ＥＢＣ涂层 观结构的影响，以及随深度变化的信息。     

电子辐照减小硅外延平面大电流开关二极管的反向恢复时间

研究了用电子辐照减小硅外延平面大电流开关二极管反向恢复时间的工艺。将未封帽的硅外延平面大电流开关二极管2CK 29的阳极面用能量1.2MeV、注量为3～5×10~(14)e/cm~2的电子束照射,可以使2 CK 29的反向恢复时间减至原来的1/4～1/8,而正向压降维持在正常范围之内。辐照器件具有良好的性能。     

定PH法测定高放废液1AW中的游离酸

前言玻璃固化处理高放废液1 AW时,要求预先了解废液中游离酸的浓度,为此,需要建立一个简便,快速,准确测定高放废液中游离酸的方法。由于高放废液1 AW中存在着UO_2~(2 ),Fe~(3 ),Al~(3 )等多种可水解离子,致使一般的酸碱滴定法无法适用。     

反应堆中子活化-多元素亚化学计量分离法测定生物和半导体材料中的Cu,Na,Au

近年来,由于Ge(Li)γ谱仪的普遍使用,亚化学计量分离法朝着多元素组分离的方向发展,亦可同时测定多种元素。 Elek和Kukala等人作了多元素亚化学计量组分离的理论研究,提出了关于MA_n类型的金属螯合物的多元素亚化学计量分离的关系式。如果指定:定量萃取(≥99％)金属离子M_i,同时保证亚化学计量(50％)萃取金属离子M_s,而金属离子M_1不被萃取,留在水相(≥99％);当等体积萃取时,有下述关系式:     

用于环境辐射剂量测量的圆柱形高气压电离室对光子能量响应的测定

用重过滤X射线束在四个方向上对圆柱形高气压电离室作了能量刻度,射线束的轴线与电离室纵轴的夹角θ分别为0°,43.6°,74°和90°。用数值积分法求得电离室对2π方向均匀照射的能量响应特性。文中还介绍了所用数值积分法的原理。     

快堆裂变中子场比释动能测定

本文介绍用国产 IRM81T-TE1型流气式组织等效电离室和低中子灵敏度的能量补偿 G-M 计数管测定快堆裂变中子和γ射线的组织比释动能率,并用美国远西公司(FWT)1C-17A 型组织等效电离室进行了对比测量,两种电离室测量结果符合很好。     

固体径迹探测器测量绝对中子注量率的一种简便法

文章叙述了用4πβ-γ符合仪器测量金箔的活性,求得所测中子场的绝对中子注量率,然后对固体径迹探测器进行刻度。由于将几个因子归并为一个简单系数,简化了公式,用时十分方便。本方法适用于任何厚度的裂变源。     

利用递次衰变关系确定新核素^239Pa的半衰期

根据合成２３９Ｐａ实验的特定条件，利用递次衰变关系首次确定了丰中子新核素２３９Ｐａ的半衰期。计算结果检验并支持了实验中合成了２３９Ｐａ的结论     

DETERMINATION OF THE SURFACE BINDING ENERGY OF A Cu/Li ALLOY BY MEASUREMENTS OF ANGULAR DISTRIBUTION OF SPUTTERED ATOMS

A copper based binary alloy containing 16.9 at % lithium has been bombarded with deuterium ions in energy range of 400 eV to 2 keV at the incidence angles of 70° and 80° away from the surface normal. The sputtered flux was condensed on Al- strips arranged arround the target in a cylindrical cup. 1.5 MeV proton backscattering and nuclear reaction 7Li(p, α)4He were used to detect the collected atoms of Cu and Li simultaneously. The angular distribution of sputtered atoms has been shown to be different for two components and strongly anisotropic for the grazing incidence. According to direct knock-on sputtering model and the experimental results the angle for the maximum differential sputtering yield is dependent on the incidence angle α, the bombarding energy E, the energy transfer factor γ= 4M1M2/(M1+ M2)2 and the surface binding energy U. With the assumption that the sputtered particles are diffracted by a planar barrier the surface binding energies of 2.3 eV for the Li component and 3.0 eV for the Cu component have been determined by fitting the measured angles of preferred ejection to the direct knock-on sputtering model, and the results agree well with a pair-binding model.     

改良型双滤膜法测定呼气的研究

本文叙述了一个用于测定呼气的改良型双滤膜装置。改良型双滤膜装置是在通用型双滤膜装置上加入了一个气溶胶输给系统,因而显著降低了原装置的壁吸附,大大提高了灵敏度。根据本文采用的程序能测出~(232)Th 在人体内最大容许体负荷量的0.03%。本方法不但能测定呼气(气土),还可以测定环境空气中的氡、(气土)浓度。本文详细介绍了该装置的原理、设备、计算方法以及测定结果。     

铀化合物中微量钽的萃取色层分离—ICP／AES测定

以CL-TBP萃取色层分离-水平式ICP/AES测定铀化合物中微量Ta。方法是先将铀化合物转化成硝酸铀酰,再以含0.2mol·l ?HF的3mol·l~(-1)HNO_3溶液溶解微量Ta,然后进行分离和测定。取样0.3g,测定下限为0.5×10~(-6);当Ta含量为1.7×10~(-6)-5.0×10~(-6)时,方法的加入回收率在88%106%范围内;相对标准偏差≤10%。     

应用双电离定方法测定15MeV中子场内化学样品中的吸收剂量

本文研究了BPT型指形TE-TE和Me-Ar电离室的特性。在由T(d,n)~4He反应产生的混合场中,对电离室的各项修正因子进行了实验测定与计算。TE-TE电离室500 V的饱和修正因子为1.007;Mg-Ar电离室200V的饱和修正因子为1.017。在15MeV中子场中应用双电离室方法测定了葡萄糖和FBX溶液体系(硫酸亚铁—苯甲酸—二甲酚橙)中的吸收剂量。确定了样品中中子吸收剂量与γ射线吸收剂量的比值。并给出了在混合场中中子吸收剂量测量不确定度为±6.3％。