2004年 第21卷 第1期
利用重叠函数的渐近归一化常数(ANC)计算了一系列核的价核子处于核外的几率及价核子密度分布的均方根半径〈r2〉1/2. 由于实验上抽取的核ANC近似与模型参数无关,因此由核ANC计算的核外几率和均方根半径是考察晕核的可靠且有效的观察量. 依价核子处于核外的几率大于50%为条件， 证实了一些核为晕核， 且给出了比较宽松的晕核出现的条件. 此外， 还用〈r2〉/R2≥1.5及〈r2〉1/2/rc≥2.0为判据考察了一系列晕核候选者. 最后， 利用r2算符在有限方势阱中的预期值给出了晕核的标度定律.
We have extracted the probability for a valence particle being out the binding potential, as well as the rootmeansquare radius of the probability distribution from the measured nuclear asymptotic normalization coefficients. According to the criterion of nuclear halo, i.e., the valence particle has larger than 50% probability being out of the nuclear binding potential, a number of halo nuclei have been confirmed. Based on these results, we have obtained a very relaxed condition for nuclear halo formation. In addition, a number of nuclear halo candidates have been analyzed with the criteria of 〈r2〉/R2≥1.5 and 〈r2〉1/2/rc≥2.0. Furthermore, we present the scaling laws for the dimensionless quantity 〈r2〉/R2 of the nuclear halo in terms of an analytical expressions of the expectation value for the operator r2 in a finite squarewell potential.
将具有负宇称的 fp 空间扩大到包含1g9/2 轨道， 采用修正的表面相互作用(MSDI)， 对64Ge, 66Ge, 68Ge, 70Se, 72Se, 74Se, 76Kr 和 78Kr等偶偶核作了形变HartreeFock计算, 得到了基态和一些激发态的解. 同时， 还用近似角动量投影形变HartreeFock（PDHF）方法对偶偶核64Ge, 74Se和奇A核79Kr进行了能谱计算， 得到其正、 负宇称带的解， 计算结果与实验谱基本一致.Using modified surface delta interaction, enlarging the fp configuration space to include the 1g9/2 orbit with the abnormalparity, the deformed HartreeFock calculations for the eight nuclei: 64Ge, 66Ge, 68Ge, 70Se, 72Se , 74Se, 76Kr and 78Kr are performed. The groundstate and some particlehole excited configurations are obtained. The approximate angular momentum projected deformed HartreeFock (PDHF) method is applied to even even nuclei 64Ge and 74Se and oddA nuclus 79Kr. Both of their normal and abnormalparity bands are obtained. The calculated energy spectra are consistent well with experimental spectra.
光子判别能力是ALICE光子谱仪PHOS的重要性能指标之一. 利用ALIROOT软件包对0.5—100 GeV能量范围随机分布的7种粒子n， p，π+， K+和γ入射到PHOS上时光子判别的效率和纯度进行模拟研究. 在簇射形状分析中， 采用主成分分析方法将7参数分析问题约简为2参数， 并与7参数拓扑分析结果进行了比较. 给出了不同能区中光子判别效率与纯度的关系.The photon discrimination power of the ALICE photon spectrometer is simulated for incident particles n， p，π+， K+and γ with random energy distribution in the range from 0.5 to 100 GeV. The pricipale component analysis method is used to reduce the number of parameters in the shower shape analysis， and the results are compared with that from the seven parameter topology analysis.The efficiency dependence of purity for the photon discrimination is obtained for the deposited energy range 0.5—10， 10—20， 20—50 and 50—100 GeV.
简单介绍了重离子治癌的原理， 叙述了一种用于重离子治癌的大面积平行板雪崩计数器， 它主要由入射窗、 x位置栅极、 中心阳极、 y位置栅极和出射窗组成. 使用C3F8气体， 气压700 Pa， 阳极电压为700 V， 两阴极接地, 电子学成形时间常数为2 μs, 测试得到的位置分辨修正后为0.54 mm(FWHM). 通过与国内外同类装置比较， 认为这一分辨已经满足了重离子治癌装置的要求. he principle of the heavyion therapy is introduced in this article. In order to precisely determine the irradiation profiles and positions of scanned heavyion beams, we developed a large area parallel plate avalanche counter(PPAC). The detector consists of one anode, two cathodes and two windows with 250 mm×250 mm active area . It was measured at an anode voltage of 700 V and with flowing C3F8 gas at the pressure of 700 Pa. A position resolution of 0.54 mm by correction was obtained with an αsource. As compared with the similar devices, we consider the position resolution of the PPAC can satisfy the requirement of the facility of heavyion therapy.
简单介绍以激光电子康普顿背散射原理为基础建立的康普顿背散射极化仪， 采用它能实时、 非破坏性地监测电子束的极化. 该项工作可作为上海激光电子γ源（SLEGS）低能γ束应用研究的内容之一.
The Compton backscattering polarimeter is described briefly on the basis of the principle of Compton backscattering in this paper. The polarization of the electron beam can be measured and monitored on time and nondestructively. The project will be one of applications of low energy γray beam of SLEGS.
简单介绍了采用炉子加热、 挥发性金属化合物和溅射产生ECR离子源的金属离子的3种方法和实验结果， 主要研究了铜、 锌、 镍和铁等多种电荷态离子的产生． 对3种方法分别进行了探讨．To satisfy the requirements of HIRFL (Heavy Ion Research Facility in Lanzhou)， series of experiments have been done to produce metallic ion beams. By now， numerous methods have been tested， in which MIVOC (Metallic Ion from Volatile Compounds)， heating oven methods and plasma sputter methods are all included. According to the experiments， the results of using MIVOC methods and heating oven methods are very good. In most of our researches， emphasis was put upon the ion production of iron， Nickel， Tantanum, copper of different charge states. Among the ion beams we have obtained， 210 μA Fe11+， 175 μA Fe12+， 142 μA Fe13+， 25 μA Fe16+， 64 μA Ni10+， 57 μA Ni13+， 31 μA Ni15+ and 15 μA Ni16+ are representative results.
利用Schottky质谱仪进行远离β稳定线核质量测量研究是九五国家大科学工程兰州重离子加速器冷却储存环上的一个重要研究方向. 简要分析了Schottky探针的工作原理和利用 Schottky质谱仪进行质量测量， 给出了对用于HIRFLCSR束流诊断与测量的Schottky探针的研制与测试结果. he mass measurement of the nuclides far from the β stability by using Schottky mass spectrometry is an important aspect of the studies on HIRFLCSR. The principle of Schottky pickup and the method and prospect of Schottky mass spectrometry are also briefly analyzed. The Schottky pickup designed for the system of diagnostics and measurement of HIRFLCSR and also the test results are given.
详细介绍了快速高压晶体管开关在加速器束流脉冲化和用于二次离子测量的加速器飞行时间谱仪上的应用. 利用飞行时间法研究了碳纳米管在不同能量的Si和Si2团簇离子轰击下氢二次离子的发射. 实验结果表明， 在每个原子质量单位的速度为2.5×108 cm/s以上， Si和Si2离子引起的氢二次离子的发射主要受电子阻止过程控制； 在每个原子质量单位的速度为2.5×108 cm/s以下和Si2团簇离子轰击的情况下， 氢二次离子的发射产额明显增加， 团簇离子在靶表面的核能损增强效应起主要作用. The application of Fast High Voltage Transistor Switches (HTS) in pulsed ion beam and the time of flight(TOF ) setup is described. Secondary ion emissions from carbon nanotubes under bombardments of MeV Si and Si2 clusters are measured by using TOF. The measurements indicate that the yield of the secondary ion emissions of hydrogen increases with increasing energy of Si and it is attributed to the electronic processes. The yield of the secondary ions of hydrogen decreases with increasing energy of Si2 clusters and the enhancement of nuclear energy loss of cluster constituents at the surface of sample plays a more significant role in the secondary ion emission of hydrogen at the low energies.
利用小波变换， 结合折叠周期分析方法， 对羊八井宇宙线观测站Tibet AS γ阵列1998年4—6月的实验记录数据进行了周期分析， 发现 TeV和10 TeV宇宙线流强观测数据中包含0.5 和1 d周期变化， 其信噪比分别达到10和6. TeV宇宙线0.5 和1 d周期变化的最大变化幅度分别约为0.3%和0.5%， 10 TeV宇宙线约为0.4%和0.7%. We use the technique of wavelet analysis and epoch folding methods to search for the superimposed periodic signals of 1—10 TeV cosmic ray in the data obtained with Tibet Ⅱ/HD AS Array for April to June of 1998. Solar time semidiurnal and diurnal variations have been detected with about signalnoise ratio 10 and 6 for the 1 TeV and 10 TeV cosmic ray flux respectively. The semidiurnal variations are of an amplitude 0.3%, a phase 0.9 for 1 TeV cosmic ray and 0.4%, 0.9 for 10 TeV. The diurnal variations are of amplitude 0.5%, 0.7%, and phase 0.8 for 1 TeV and 10 TeV cosmic ray respectively.
用能量为22 MeV/u的 Fe离子在室温和真空条件下辐照了多层堆叠的半晶质聚酯膜, 采用傅里叶转换红外吸收光谱、 紫外/可见吸收光谱 和X射线衍射技术分析测量了辐照后聚酯膜的微观结构所发生的变化, 详细研究了分子结构的变化和非晶化转变与离子剂量、 离子在样品中的平均电子能损以及吸收剂量的依赖关系． 分析结果表明: 辐照导致化学键的断裂、 新化学键的形成和非晶化转变． 非晶化效应和化学键的断裂随离子剂量和电子能损的增加而增大, 但变化的总量仅依赖于总的吸收剂量, 表明在所涉及的能损范围里, 辐照产生的变化与辐照离子的种类和能量没有直接的关系, 而只决定于材料对辐照离子能量的吸收程度．
Semicrystalline polyethylene terephthalate (PET) film stacks were irradiated with 22 MeV/u Fe ions at room temperature under vacuum. Ion beam induced microscopic structural modifications and amorphous transformation were investigated by means of Fourier transform infrared spectrosocopy (FTIR), ultraviolet visible absorption spectrosocopy (UV/Vis) and Xray diffractometer (XRD). It was found that irradiation induces bond breaking, formation of new free radiculs and amorphous transformation. These effects were found to depend on ion fluence , the electronic energy loss and aborbed dose. The creation of alkyne groups was found only at the aborbed dose higher than 5.0 MGy.
列举了一些具有代表性的研究结果， 概括介绍了一些产生旁观者效应的可能机制以及辐照引起的活性氧基团或分子、 细胞通讯和细胞因子在旁观者效应中的重要作用. 此外， 还讨论了旁观者效应的表达程度与辐照剂量和射线品质的关系. 旁观者效应的研究结果表明： 辐射产生的潜在危害可能要比以前估计的大， 这给如何评估辐射对人类造成的危害带来了新的冲击.
Recent studies have indicated that biological effects, such as chromosomal aberration, gene mutation and cell death and so on, can be induced in cells that are not traversed by radiation directly. This phenomenon has been termed as bystander effects. In this paper, a few representative studies were reported and the possible mechanisms underlying the bystander effects were summarized. The reactive oxygen species (ROS) induced by ionizing radiation, cellular communication and some factors play important roles. Besides, the expression extent of bystander effects depended on radiation dose and quality were discussed. Bystander effects suggest that potential health risks associated with radiation exposure may be greater than those of original thought and this makes ultimate impact on human radiation risk assessment.
以不同剂量照射后的细胞存活率、 微核率和微核细胞率作为生物学终点, 研究了γ射线对A172细胞的生物学效应. 结果表明: 细胞存活率与剂量之间满足回归方程lgY=-0.064 27X+1.833 54, 其回归系数r=-0.988 6, P<0.01. 剂量为1 Gy时微核率和微核细胞率达到最大值, 此时的微核率为（66.75±3.564）%, 微核细胞率为（53.9±0.784 9）%, 微核率和微核细胞率均随着剂量的增大先增大后减小, 并分别维持在42%和37%左右. To study the biological effectiveness in A172 glioma cells induced by γray irradiation, the survival fraction and the micronucleus frequency of A172 cells was measured. The result showed that the survival fraction was negatively correlated to the radiation dose. At 1.0 Gy, the micronucleus frequency peaked about (66.75±3.564)%, and the frequency of micronucleus cells peaked about (53.9 ±0.784 9)%. As the radiation dose increasing, the micronucleus frequency and the frequency of micronucleus cells decreased and finally kept steady about 42% and 37%, respectively.
分析了在高蛋白质谷物育种中对筛选方法的要求， 对谷物中蛋白质测定的方法进行了综述评价， 重点介绍了用于谷物蛋白质测定的核反应分析法的原理及特点. The requirements of the screening method for high protein content in grain breeding are analysed. Methods for the determination of protein content in grain seed are reviewed.The principle and the advantages of the nuclear reaction method for the measurement of protein content in grain seed are discussed in detail.
利用曾经提出的正弦平方势解析地处理了非线性效应和偶极效应对沟道谱线宽度的影响， 解释了正电子能量在5 GeV附近的Si (110)面沟道辐射谱特征.
The spectral properties of the planar channeling radiation of positron have been investigated by using Sinesquared Potential. At positron energy of 5 GeV a sharp line has been explained for the planar channeling radiation in Si(110 ). It is that theoretic results are compatible to the experiments.
在对KⅧ—TbLⅣ离子3s3p3P1能级结构的多组态相互作用理论HXR方法计算的基础上， 分析了各种效应对等电子序列离子能级结构的影响， 找出了能级沿等电子序列变化的规律性. 预测计算了KⅧ—TbLⅣ离子3s3p3P1的能级. 由此进一步计算了KⅧ—TbLⅣ离子自旋禁戒跃迁3s3p3P1—3s21S0的谱线波长、 振子强度和跃迁概率.
We have calculated the energy levels of 3s3p3P1 for magnesiumlike sequence ions from KⅧ—TbLⅣ by HXR (HartreeForck plus statisticalexchange potential with relativistic corrections) method. With the important effects taken into account， we have made a systematic fit for the energy levels of the ions mentioned above. We predicted here the energy levels which have not been observed in experiments for ions from KⅧ to TbLⅣ.The wavelengths， oscillator strengths and probabilities of intercombination transitions 3s3p 3P1—3s21S0 are computed too.
为了确定加速器驱动系统中少錒系核素的核数据的不确定性对此系统中积分参数的影响， 选择一铅铋冷却次临界系统来进行分析， 选择不同的微观评价库CENDL3.0 ， JENDL3.2及ENDF/BVI.6， 并只考虑20 MeV以下的中子产额， 来计算次临界系统的积分参数. 以ENDF/BVI.2 库的计算结果作为参考结果， 依次用CENDL3.0库及JENDL3.2库中相应的錒系核素替换ENDF/BVI.6 库中的錒系核素， 计算了次临界系统的Keff值及反应率， 并就变换主要錒系核素时对所计算的Keff值及反应率的影响进行了分析、 比对. 在堆芯处， 当改变錒系核素时Keff值总的变化为30%， CENDL3.0的238Pu的弹性散射反应率比ENDF/BVI 库的结果高出10%， ENDF/BVI 库的242Am的裂变率超过了CENDL3.0库的15%. In order to investigate the effect of minior actinide data on integral parameter, the acceleratordriven minior actinide benchmark system was selected in this work. The library based on ENDF/BVI.2 was used for the reference calculation. The sensitivities were examined by exchanging the minior actinides of CENDL3.0 and JENDL3.2 one after another. The Keff values and reaction rates were calculated. According to the comparisons, the difference in Keff from the refrence is more than 3‰, and the fission reaction rate of 242Am is about 15% lower than those of reference results. The elastic scattering reaction rate of 238Pu of CENDL3.0 is about 10% larger than those of ENDF/BVI.