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2010年  第27卷  第4期

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核物理
Gammasphere 上裂变丰中子核核结构若干前沿领域的新进展(II: 第三和第四部分)(英文)
罗亦孝, J.H.Hamilton, J.O.Rasmussen, A.V.Ramayya, C.Goodin, A.V.Daniel, N.J.Stone, 朱胜江, J.K.Hwang, 刘少华, C.J.Beyer, 李科, H.L.Crowell, D.Almehed, S.Frauendorf, A.Covello0, V.Dimitrov, 张敬业, 车兴来, 姜卓, D.Fong, A.Gelberg, I.Stefanescu, A.Gargano0, E.F.Jones, P.M.Gore, I.Y.Lee, G.M.Ter-Akopian, Yu.Ts.Oganessian, M.A.Stoyer, R.Donangelo, 马文超, J.D.Cole, J.Kormicki, 张学谦, S.C.Wu, J.Gilat, T.N.Ginter, S.J.Asztalos0
2010, 27(4): 363-389. doi: 10.11804/NuclPhysRev.27.04.363
摘要:
  使用Gammasphere 多探测器系统对252Cf 裂变源瞬发γ射线进行γ-γ-γ和γ-γ(θ) 符合测量, A~100 (Z~40, N>56)丰中子核区关于形状过渡、形状共存和形状突变的深入研究获得了新的进展。 奇Z核的系统研究揭示了从Z=39 (Y) 同位素的轴对称大四极形变到Z=43 (Tc), 44 (Ru)和45 (Rh)同位素中具有中等四极形变之大三轴形变的过渡。 Nb (Z=41)同位素具有过渡核的特征。 根据邻近同位素和同中素带交叉信息的系统性及推转壳模型(CSM)计算, Tc和Rh偶-N同位素中观察到的带交叉产生于一对h11/2 中子的转动顺排。 首次观察到100Nb (Z=41, N=59)的高自旋能级纲图和形变态, 从而证实了100Nb中的形状共存, 并确认, 在Nb同位素链上, 基态形状突变发生于N=58(球形)到N=59 (大形变); 而在Sr (Z=38), Y (Z=39) 和Zr (Z=40) 各同位素链上, 基态形状突变均发生于N=59(球形)到N=60 (大形变)。100Nb具有大形变基态, 同现有理论预言相矛盾, 其大形变的基态及转动带所具有的很大的和不规则的转动惯量具有重要的理论意义。 
  对奇-质子Cs (Z=55) 和 La (Z=57) 丰中子同位素八极激发的详细研究, 发现了141, 143, 144Cs同位素链上电二极矩D0随中子数增加而减小的急剧变化, 此前在145,147La 中观察到的电二极矩D0的较缓和的减小似乎亦很陡地下延至148La。在Cs 和La 同位素中观察到的电二极矩D0的急剧下降很可能同偶-质子核146Ba和224Ra中观察到的电二极矩D0的急剧下降相类似, 后者已获反射非对称平均场壳修正理论的成功解释。 实验证明, 141Cs 具有很大电二极矩D0141Cs和142Xe 中观测到的很大的电二极矩D0和仅在141Cs 中观察到的电二极矩D0的simplex 量子数相关性需要进一步的理论研究。 根据转动频率比值ω-(I)/ω+(I)的检定, 同Xe同位素一样, 认定Cs同位素中包括143Cs的八极激发为八极振动, 而在La同位素中存在八极形变。
  By means of γ-γ-γ and γ-γ(θ) measurements of prompt fission γ rays from 252Cf using Gammasphere, new insights have been gained into the A~100 (Z~40, N>56) neutron rich region, which has long been of interest for shape transitions, shape coexistence and onset of deformations. The systematic investigations of odd-Z isotopes have revealed a shape transition from axially symmetric shapes with very large quadrupole deformations in Z=39 (Y) to near maximum triaxial shapes with moderate quadrupole deformations in Z=43 (Tc), 44 (Ru), 45 (Rh) isotopes. The Nb (Z=41) isotopes are found to be transitional with regard to this shape transition. The bandcrossings observed in the evenN Tc and Rh isotopes are attributed to alignment of a pair of h11/2neutrons. The longexpected sudden shape transition in Nb isotopic chain is now observed. The longsought highspin level scheme and deformed states in 100Nb (N=59) were identified. The ground state of 100Nb was found to be strongly deformed, in disagreement with existing theory. The shape coexistence was confirmed in the nucleus, and the sudden shape transition in the Nb isotopic chain was seen to occur between N=58 (spherical) to N=59 (strongly deformed), in contrast to the sudden shape transition from N=59 (spherical) toN=60 (strongly deformed) in Sr (Z=38), Y (Z=39) and Zr (Z=40) isotopic chains. The observation of strongly deformed ground state in 100Nb and its very large and irregular moments of inertia make 100Nb an especially interesting case for further theoretical studies.
  Recent detailed studies of octupole excitations in odd-Z Cs (Z=55) and La (Z=57) isotopes have discovered a sharp drop in electric dipole moments D0 in the Cs isotopic chain 141, 143, 144Cs, and, most likely, the previously reported moderate drop in D0 in 145, 147La is extended sharply down in 148La. The sharp drops of D0 in Cs and La are most likely analogous to those reported in 146Ba and 224Ra, which were accounted for by the reflectionasymmetric mean field shell correction theory. The very large D0 in both 141Cs and 142Xe and the simplexdependent D0 deduced in 141Cs but not in 143Cs need further theoretical studies. Based on rotational frequency ratios, ω-(I)/ω+(I), octupole vibrations are proposed in Cs isotopes, like the cases in Xe isotopes, while octupole deformations are suggested in La isotopes.
利用中高能破碎和敲出反应研究非稳定核结构
叶沿林, FAISAL JamilQureshi, 楼建玲, 葛愉成, 吕林辉, 曹中鑫, 肖军, 李奇特, 陈天逸, 杨帆
2010, 27(4): 390-398. doi: 10.11804/NuclPhysRev.27.04.390
摘要:
中高能区的破碎和敲出反应, 由于机制相对简单、 对核的表面敏感、 理论处理比较成熟等原因, 在非稳定核的晕结构、 壳移动等奇特性质研究中发挥了独到作用。 针对次级束流强度较弱、 能散较大等特点, 实验上发展和应用了逆运动学有效立体角完全测量、 轻重靶结合、 高精度消色差磁谱仪、 前向中子谱仪、 在束γ测量等技术手段, 大大提升了实验的探测能力和选择性。 从物理问题探索和实验路线演变的角度, 回顾了非稳定核破碎和敲出反应的发展过程与启示, 并探讨未来的走向。 The breakup and knockout reactions at intermediate and high energies are of the advantages such as simple reaction mechanism, sensitive to the surface of the nucleus, mature theoretical treatment and so on, and therefore have been applied successfully to the study of exotic structure of unstable nuclei. In order to deal with the problems of the secondary beam which often has large beam spot size and energy spread, the special experimental methods and techniques, such as inverse kinematics complete detection, combining light and heavy targets, high resolution dispersionmatch magnetic spectrometer, forward neutron spectrometer, inbeam γ spectroscopyetc, have been developed and applied over the time, allowing much improved detection capability and sensitivity. This report gives an overview of the progress made with the breakup and knockout reactions for unstable nuclei study, based essentially on the new physics explored and the evolution of the experimental method applied. Possible future developments are also discussed.
Delta Excitation in Compressed NeutronRich Double Magic Spherical Finite Nucleus 132Sn
Mohammed H. E. Abu-Sei’leek
2010, 27(4): 399-410. doi: 10.11804/NuclPhysRev.27.04.399
摘要:
The ground state properties of 132Sn at equilibrium and at large compression are investigated, within the framework of the radially constrained spherical HartreeFock(CSHF) approximation. The delta resonance effects on the properties of neutronrich double magic spherical nucleus, 132Sn, in its ground state and the state under static compression are studied. The sensitivity of the nucleon size and Δ model spaces is investigated. At equilibrium, mixing between nucleon and Δ’s in the largest model space of nine major nucleon shells plus 10 Δ orbitals was found. Expanding the nucleon model space has a larger effect on reducing the static compression modulus and softening the nuclear equation of state than increasing the number of Δ states. It was found that the most of the increase in the nuclear energy generated under compression is used to create the massive Δ particles. For 132Sn nucleus under compression at 12 times the normal nuclear density, the excited nucleons to Δ’s increased sharply up to 13% of the total number of constituents. This result is consistent with the values extracted from relativistic heavyion collisions. The single particle energy levels calculated and their behaviors under compression are examined too. A good agreement between results with effective Hamiltonian and the phenomenological shell model for the low lying singleparticle spectra is obtained.
氘核破裂效应对质子出射能谱的贡献(英文)
安海霞, 蔡崇海
2010, 27(4): 411-415. doi: 10.11804/NuclPhysRev.27.04.411
摘要:
基于连续离散化耦合道理论(CDCC), 并在假设剩余核不仅可处于束缚态而且可处于一系列的激发态的基础上, 本工作论述了氘核破裂效应对质子出射能谱的贡献。计算结果可以基本解释质子出射能谱在大约氘核入射能量一半处出现峰值结构的实验现象。本工作的计算结果与C.Kalbach的经验公式基本保持一致。Based on the continuum discretized coupled channels(CDCC) theory, and the hypothesis that the residual nucleus locates not only in bound state but also in a series of excited states, the contribution of deuteron breakup effect in outgoing proton energy spectra are studied in the present work. And the results can basically explain the experimental results that a peak structure is appeared in the outgoing proton energy spectra at about half of the incident energy. The results of present calculation generally agree with those obtained from C. Kalbach’s empirical formulaum.
核子-核子碰撞截面的参数化公式
魏慧玲, 于勉, 马春旺, #
2010, 27(4): 416-420. doi: 10.11804/NuclPhysRev.27.04.416
摘要:
核子-核子碰撞截面(σNN)是描述原子核反应模型中的重要物理量。 核子-核子碰撞截面包括质子-质子碰撞截面(σpp)、中子-中子碰撞截面(σNN)和中子质子碰撞截面(σnp), 它们随着核子能量与核物质密度的改变而变化。人们在目前研究中提出了多种核子-核子碰撞截面关于能量和核物质密度的参数化公式,通过计算12C+12C的完全反应截面,比较了不同入射能量下使用各种核子-核子碰撞截面参数化公式对12C完全反应截面的影响。 The nucleus-nucleus cross sections(σNN) include the proton-proton cross section, neutron-neutron cross section, and neutron-proton cross section. σNN change with the variations of the incident energies and the densities. Some parameterizations of σNNas a function of incident energy and density have been proposed in the theoretical and experimental study of nuclear reactions. Through the calculation of reaction cross sections of 12C+12C at different energies, the effect of different σNN parameterizations in the reaction cross sections of 12 are studied.
高能Cu+Cu碰撞中末态带电粒子赝快度分布的能量与对心度依赖性
姜志进, 孙玉芬
2010, 27(4): 421-425. doi: 10.11804/NuclPhysRev.27.04.421
摘要:
利用Glauber模型,给出了核-核碰撞中的参与者数及二元核子-核子碰撞数与碰撞参数的解析关系,并以此为基础,在考虑到参与者由于多重碰撞而引起的能量损失效应后,通过有效二元核子-核子碰撞末态带电粒子赝快度分布的加权叠加,建立起了以碰撞参数为自变量的核-核碰撞末态带电粒子的赝快度分布函数, 并用其分析了RHIC-PHOBOS合作组在不同能量与不同对心度的Cu+Cu碰撞中所做的实验测量。 所得结果与实验符合得较好。Using Glauber model, we present the impact parameter dependences of the numbers of participants and binary nucleon-nucleon collisions in nucleus-nucleus collisions. Then, on the basis of this work,after considering the effect of energy loss of participants in their multiple collisions,we get the pseudorapidity distributions of charged-particles as a function of impact parameter in nucleus-nucleus collisions through weighted superposition of the distributions in effective binary nucleon-nucleon collisions. The experimental measurements carried out by RHIC PHOBOS Collaboration in different central Cu+Cu collisions at different energies were analyzed by using this model. The theoretical results are well consistent with the experimental observations.
高能核-核碰撞中直接光子各向异性的数值模拟研(英文)
马科, 朱光喜, 周代翠
2010, 27(4): 426-431. doi: 10.11804/NuclPhysRev.27.04.426
摘要:
通过计算给出了在LHC能区非对心核核碰撞中由椭圆流ν2 表示的高横动量直接光子的方位角不对称性。该高横动量光子是由喷注与热密介质相互作用而辐射出来的。光子椭圆流与强子椭圆流ν2 相差π/2的相位, 是直接光子椭圆流中负值的来源。同时, 计算表明LHC能区直接光子ν2随粒子横动量pT的变化趋势与RHIC上的实验结果一致, 但LHC能区较RHIC能区有更低的直接光子流ν2 值, 且ν2 值由负到正对应的转换pT值更高。这表明在LHC能区喷注淬火效应更为明显, 表面发射的直接光子对光子椭圆流的贡献份额增强。The azimuthal anisotropy of high pT direct photons is investigated by using the coefficient of elliptic flow ν2 in non-central nucleus-nucleus collision at LHC energies. These photons come from radiation induced by the interaction between jet and hot/dense medium. The azimuthal anisotropy of high pT direct photons is investigated by using the coefficient of elliptic flow ν2 in non-central nucleus-nucleus collision at LHC energies. These photons come There is π/2 difference between direct photons and hadrons for the azimuthal elliptic flow ν2. Such photons are the main source of the negative part of ν2 for direct photons. The dependence of the direct photon ν2 on the transverse momentum pT at LHC energy is found to be consistent with the experimental results at RHIC energy. Furthermore, we find that the value of the direct photon ν2 at LHC energy is smaller than that at RHIC energy. The value of the transverse momentum at which the direct photon ν2 changes from negative value to positive at LHC is higher than that at RHIC. It’sfound the enhanced jetquenching effect and enhanced contribution for the elliptic flow ν2 of the direct photons emitted from surface at LHC energy.
多分量对偶超导理论和口袋模型
王纯锴, 邹丽平, 张鹏鸣, #
2010, 27(4): 432-435. doi: 10.11804/NuclPhysRev.27.04.432
摘要:
基于联络新参数化方案研究了多分量对偶超导模型。给出了多分量GinzburgLandau模型中的自对偶解, 并研究了磁通量子数趋于无穷大时的墙涡旋解, 以及与口袋模型之间的联系。The multi-component dual superconductor theory has been studied based on
the new parameterization of gauge potential. The selfdual vortices of the multicomponent GinzburgLandau model was investigated. Then we considered the wall vortex whose flux goes to infinity. At last, the relationship between the bag model and wall vortices is considered.
加速器
低β四分之一波长腔中的束流偏转的分析性研究(英文)
张聪, 赵红卫, 何源
2010, 27(4): 436-439. doi: 10.11804/NuclPhysRev.27.04.436
摘要:
目前加速速度范围在0.01 c—0.3 c 的粒子的超导腔主要使用四分之一波长腔型。用于不同加速器上的频率范围在50—240 MHz 的四分之一波长腔在建造或者预研中。这种腔型的一个不足是其横向电磁成分会造成束流偏转效应,从而导致发射度的增长和束流的溢漏, 在强流重离子加速器中这种效应尤为严重。对中国科学院近代物理研究所超导直线加速器中的频率为80.5和161 MHz的四分之一波长腔的偏转效应进行了分析,计算结果表明,在四分之一腔体的设计时需要考虑到束流偏转的修正, 这通常需要在漂移管端面上削适当大小的倾角来实现。Superconducting(SC) cavities currently used for acceleration of ions in the velocity range from 0.01 cto 0.3 c are based frequently on quarterwave resonators(QWR). Various types of QWR cavities across a frequency extent from 50 to 240 MHz have been constructed or are proposed for numerous applications. A drawback of this kind of cavities is the beam steering caused by transverse magnetic and electric field components, which can creat emittance growth. In this paper, the analytical studies on beam steering in quarter wave resonator of frequency=80.5 and 161 MHz of the SC linac has been done in Institute of Modern Physics, Chinese Academy of Sciences, the calculated results have told us that the correction for beam deflection should be a consideration during the design of the QWR cavity, which generally involves the shaping the inner drift tube.
FAIR项目Super-FRS超导二极磁铁端部优化
姚庆高, 马力祯, #, 张小奇, 何 源, 袁平, 张斌, 吴巍, 韩少斐, 张思玲
2010, 27(4): 440-444. doi: 10.11804/NuclPhysRev.27.04.440
摘要:
介绍了Super-FRS超导二极磁铁的磁场优化和端部削斜方案,采用OPERA软件对活极头进行削斜计算,得出合理的活极头尺寸,使各场下的积分均匀度在要求范围内达到了±2×10-4。最后将计算的积分场均匀度与磁场测量的结果进行比较,结果吻合得较好,验证了这种端部活极头优化计算方法的正确性。 The end optimization of dipole magnet of Super-FRS for FAIR by OPERA 3D has been introduced in this paper. By using a complicated chamfer, the integral field homogeneity which is better than 2×10-4 can be obtained. In addition, the paper also introduced the comparison between the magnetic field measurement result and calculation one, which confirms the method of the removable pole end chamfer very well.
核技术
基于GEANT4的CsI(Tl)闪烁体探测器的Monte Carlo模拟
岳珂, 徐瑚珊, 梁晋洁, 孙志宇, 王建松, 苏光辉, 胡正国, 陈若富, 肖志刚, 郑川, 张雪荧, 涂小林, 陈金达, 章学恒, 陈俊岭
2010, 27(4): 445-449. doi: 10.11804/NuclPhysRev.27.04.445
摘要:
对闪烁光在晶体内的传输以及光电子倍增过程进行了建模,基于GEANT4软件包对CsI(T1)闪烁体探测器进行了蒙特卡罗模拟, 得到了不同形状、尺寸和包装的CsI(Tl)晶体测量γ射线的能谱。对比模拟和测试结果,两者得到了很好的符合,从而验证了模拟参数的合理性和可靠性。该模拟程序的建立为闪烁体探测器的设计提供了更精确的开发工具。 With the modeling of the light transportation in crystal and electron multiplication in the PMT, a Monte Carlo simulation of CsI(Tl) scintillator detector has been implemented with Geant4 toolkit. The energy spectra simulated with different crystal shape, size and wrappings are obtained. And the reliability of the simulation parameters is confirmed by comparing with the measurements. The simulation code can be used as an reliable tool for the design of scintillator detectors.
用于高能轻粒子探测的延迟线PPAC(英文)
耿朋, 段利敏, 马朋, 鲁辰桂, 徐瑚珊, 王建松, 唐彬, 徐治国, 鲁皖
2010, 27(4): 450-454. doi: 10.11804/NuclPhysRev.27.04.450
摘要:
气体探测器有成本低廉、制备简单、性能可靠和方便使用等特点。研制了一种5层板结构的延迟线平行板雪崩电离室(PPAC),用于兰州放射性束流线(RIBLL)上开展的实验。在57.6 MeV/u的6He束流条件下测试了这种探测器对高能轻粒子的适用性,得到了位置分辨为1.8 mm (FWHM), 时间分辨为2.6 ns, 以及可靠的探测效率。The gas detectors have the characteristics of low cost, easy preparation, reliable capability and convenient for use etc. A delayline parallelplate avalanche counter(PPAC) with five plates has been developed for the experiments at Radioactive Ion Beam Line in Lanzhou(RIBLL). The applicability of counter for high energy light ion has been tested with 57.6 MeV/u 6He beam. A position resolution of ~1.8 mm(FWHM) and a timing resolution of ~2.6 ns are achieved. The detection efficiency is reasonable.
一种用于DT聚变诊断的新型中子谱仪的设计
周林, 蒋世伦, 祁建敏
2010, 27(4): 455-458. doi: 10.11804/NuclPhysRev.27.04.455
摘要:
介绍了一种基于反冲质子法和磁分析技术的新型DT聚变中子谱仪, 能够以高信噪比对9—17MeV的中子能谱进行精确测量, 适用于稳态及脉冲条件下的等离子体温度(Ti)和燃料面密度(<ρR)的诊断, 对14 MeV的初级DT中子具有约4%的能量分辨率和约10-8的探测效率。谱仪的磁分析系统使用高性能钕铁硼二极永磁铁建造, 焦平面上使用CR-39固体径迹探测器测量反冲质子的位置分布。使用239Pu α源对磁分析系统进行了实验研究,并建立了配套的粒子输运模拟程序。 结合实验和程序模拟结果,使用蒙特卡罗软件模拟分析了谱仪整体性能。 谱仪结构紧凑、性能良好且适用于稳态及脉冲辐射场,可望在未来的聚变研究中得到有效应用。
Design of a novel spectrometer for measurements of neutrons in the energy range 9—17 MeV has been proposed. Based on proton recoil method and magnetic analyzing technigue, the spectrometer can be used to determine DT fuel areal density(<ρR) and ion temperature under steady state and pulsed radiation field. The detection efficiency is about 10-8 for measuring 14 MeV neutrons with an energy resolution of about 4%. A neodymiumironboron permanent dipole was used for the magnetic analyzing system and CR-39 track detectors were used in the focal plane. The system has been tested with 239Pu α suorce and a corresponding particle transport simulation program has been worked out. Performance of the spectrometer was investigated with Monte Carlo simulation, experiment data and the transport simulation. Due to its good performance, compact structure,and availability for both steady state and pulsed radiation field, the spectrometer can be effectively used for fusion research in the future.
用于粒子探测器的CMOS FET采样保持电路的设计与仿真(英文)
WEMBE TAFO Evariste, 苏弘, 千奕, 周朝阳, 王同喜
2010, 27(4): 459-463. doi: 10.11804/NuclPhysRev.27.04.459
摘要:
介绍了一个峰保持电路。该电路适用于silicon strip, Si(Li), CdZnTe and CsI 等探测器,实现采样保持功能。 已成功进行了基于CMOS FET的采样保持电路的设计和仿真, 通过使用Proteus的PSPICE仿真器和BSIMV3.3模型参数完成了电路性能的仿真。同时,实现了采样时间可在 60 ns 到 4.44 ??s范围内进行选择, 该电路具有较好的线性。In this paper, the objective is to realize a Track/Hold Circuit for silicon strip, Si(Li), CdZnTe and CsI detectors etc. By using CMOS transistor to implement various components in electronic circuit, the Track and Hold circuit only made with CMOS FET is succeeded to be designed and simulated. Performance was characterized using PSPICE simulator with BSIMV3.3 parameters of the Proteus. Several measurements of acquisition time can be made from 60 ns to 4.44us related to the output resistance, and the integral nonlinearity is good.
兰州重离子加速器团簇内靶装置控制系统设计
王彦瑜, 林飞宇, 张建川, 刘伍丰, 肖文君, 邵曹杰
2010, 27(4): 464-468. doi: 10.11804/NuclPhysRev.27.04.464
摘要:
介绍了兰州重离子加速器冷却储存环(HIRFL-CSR)的实验环(CSRe)团簇内靶装置控制系统的设计。 该内靶系统由多种设备构成,包括喷嘴测温与加热控制子系统、真空与阀门监测/控制子系统、分子泵监测与控制子系统、数据处理与流程软件子系统等部分。该系统在内靶实验中工作状态良好,满足了内靶实验的需求。在该控制系统的支持下,2010年1月第一轮辐射电子俘获物理实验顺利完成。 It is described in this paper the design of the control system for HIRFLCSRe internal target facility, in which there are many different kinds of units need to be monitored and controlled. The control system is composed of several subsystems which are designed to control the gasjet temperature, chamber vacuum, valves and molecular pumps. A humancomputer interaction interface is also realized to do the data acquisition, data processing and display. The whole system has been working stably and safely, it fully meets the requirements of physical experiments in the internal target facility. In January of 2010, the first physics experiment of the radioactive electron capture was finished successfully with the aids of this control system.
交叉学科
不同LET辐射致DNA集簇性损伤的研究
徐辉辉, 隋丽, 刘晓丹, 汪黎, 王潇, 王豫, 徐勤枝, 周平坤, #
2010, 27(4): 469-473. doi: 10.11804/NuclPhysRev.27.04.469
摘要:
利用辐照质粒DNA构象变化的分子模型,以DNA糖苷酶Fpg和AP核酸内切酶Endo III 识别并切割辐射所致DNA碱基损伤, 将其转换为DNA断裂损伤,通过电泳分析DNA分子构象变化, 研究比较γ射线、质子和7Li离子诱发DNA集簇性损伤。50 Gy以上高剂量γ辐射对质粒DNA的损伤主要表现为单链断裂(SSB)和很少比例的双链断裂(DSB),并能产生一定水平的集簇性损伤。相比之下,高能质子束和高LET的7Li离子直接所致DNA的断裂损伤以及所产生的集簇性碱基损伤比γ射线的要严重,质子10 Gy照射就可诱发明显的集簇损伤。Based on the molecular model of conformation changes of plasmid DNA, the DNA damages induced by γrays, proton and 7Li ion were studied and compared. In order to detect the clustered DNA damage, the irradiated plasmid DNA was digested with E Coli formamidopyrimidine DNA glycosylase (Fpg) and AP endonuclease III (Endo III) which convert the damaged bases and AP sites into singlestrand breaks (SSB), and then subjected to agarose gel electrophoresis. The results indicated that SSB, a certain level of clustered bases lesions and a tiny of doublestrand breaks (DSB)were induced by the observed 50—200 Gy of γrays. The DNA breakage and clustered bases lesions induced by high LET proton and 7Li ion were much higher as compared with that induced by γrays. Our data also showed that an obvious clustered DNA damage was induced by proton even at 10 Gy dose, and the effectiveness of DNA damage induction by proton was higher than that of 7Li ion.
基于细胞群模型的放射生物学分析
林辉, 景佳, 孟大敏, 徐元英, 许良凤
2010, 27(4): 474-479. doi: 10.11804/NuclPhysRev.27.04.474
摘要:
采用放射生物学方法,研究了放射性核素靶向治疗中细胞群大小对EUD和TCP的影响, 并以宏观与微观结合的方法,分析了肿瘤中心活性缺失情况下所对应的特征。 研究表明, 在活性均匀分布的情况下,EUD随细胞群(肿瘤)增大而增大。若考虑细胞间液活性的影响, EUD还会增加约47%。当肿瘤内部活性缺失时,若以TCP= 0.90作为衡量标准,周围细胞的211At α粒子的交叉效应,对于细胞核源最大可弥补边长为4层细胞的肿瘤活性中空,而其它源可弥补边长为6层细胞的肿瘤活性中空。临床治疗中,医师按照模拟结果参考给药时,应参考细胞面源的指导药量,以免由于剂量不足而造成的肿瘤控制的局部失败。TCP可以清晰地表现剂量足与不足时的差异,但是当剂量充足或过量时效果就要差些,因此它比较适合于治疗计划的制定。EUD常用于比较不同活性分布的差异,但用户在使用时一定要注意保持前后模型形状、体积的一致性。 The influence of cell cluster dimension on EUD and TCP for targeted radionuclide therapy was studied using the radiobiological method. The radiobiological features of tumor with activity lack in core were evaluated and analyzed by associating EUD,TCP and SF. The results show that EUD will increase with the increase of tumor dimension under the activity homogeneous distribution. If the extracellular activity was taken into consideration, the EUD will increase 47%. Under the activity lack in tumor center and the requirement of TCP=0.90, the α crossfire influence of 211At could make up the maximum(48 μm)3 activitylack for Nucleus source, but (72 μm)3 for Cytoplasm, Cell Surface, Cell and Voxel sources. In clinic, the physician could prefer the suggested dose of Cell Surface source in case of the future of local tumor control for underdose. Generally TCP could well exhibit the effect difference between underdose and duedose, but not between duedose and over dose,which makes TCP more suitable for the therapy plan choice. EUD could well exhibit the difference between different models and activity distributions,which makes it more suitable for the research work. When the user uses EUD to study the influence of activity inhomogeneous distribution, he should keep the consistency of the configuration and volume of the former and the latter models.
初步的IMP重离子治疗计划系统
刘新国, 李强, #, 杜晓刚, 王阳萍, 戴中颖, 叶飞, 吴庆丰, 金晓东, 李萍, 党建武
2010, 27(4): 480-487. doi: 10.11804/NuclPhysRev.27.04.480
摘要:
中国科学院近代物理研究所基于兰州重离子研究装置(HIRFL/HIRFL-CSR), 在被动型束流配送系统下采用二维分层适形照射治疗技术开展重离子治癌临床试验研究。 为了更好地利用重离子束在肿瘤放射治疗中的生物物理优势并保障重离子临床治疗试验的顺利实施, 一个初级版本的重离子治疗计划系统已经设计完成。 此计划系统是针对被动型束流配送系统下的二维分层适形照射治疗方式来进行设计的。 介绍了此系统的设计框架、 可提供的功能以及利用宽束算法进行剂量计算在此系统中的实现。 通过人体仿真体模实验证实由该治疗计划系统给出的靶区计划剂量与实测剂量的偏差在5%之内。 最后讨论了设计较为完备的重离子治疗计划系统仍需解决的问题。 Based on the Heavy Ion Research Facility in Lanzhou(HIRFL/HIRFLCSR), clinical trials of heavy ion radiotherapy are being conducted at the〖HJ*4/9〗 Institute of Modern Physics(IMP), Chinese Academy of Sciences, where twodimensional(2D) layerstacking conformal irradiation method in a passive beam delivery system was applied. To make better use of the biophysical advantages of heavy ion beams and ensure success of the clinical trials, a preliminary version of heavy ion treatment planning system(TPS) has been developed at IMP. The TPS was designed in a manner to adapt to the 2D layerstacking conformal irradiation method. The architecture and function of the TPS software and the implementation 〖HJ〗of dose calculation algorithm in the TPS were introduced in this paper. The deviation between the doses planned by the TPS and measured through an anthropomorphous phantom was verified to be less than 5%. Finally, the pending issues for developing a sophisticated treatment planning system at IMP were discussed.
植物个体远程辐射信号早期传递过程的研究体系创建
王婷, 李方华, 徐淑艳, 卞坡#, 吴跃进, 吴李君
2010, 27(4): 488-492. doi: 10.11804/NuclPhysRev.27.04.488
摘要:
自2005年以来,活体中的远程辐射旁效应逐渐成为辐射生物学的研究热点, 然而其早期信号传递过程的相关研究却鲜见报道,主要原因是由于早期信号传递过程研究所需的旁区与辐射区的自由分离与组合在动物模型上无法实现。 本研究是基于植物个体可以切割和嫁接的特性, 借鉴离体细胞培养基转移方法研究旁效应早期过程的思想, 在植物个体上实现旁区与辐照区的“分离”与“组合”,构建了一种研究个体远程辐射信号早期传递过程的植物实验体系。 具体是以模式植物拟南芥菜转基因系(AtRAD54promoter∶∶GUS)为材料, 同源重组修复相关基因AtRAD54表达水平为生物学检测终点,人为地将辐照区的组织(或器官)与旁区部分“分离”或“嫁接”,通过测定旁区组织(或器官)的AtRAD54基因表达水平变化,研究其辐射信号传递的早期过程。该研究体系的创建为活体旁效应早期过程的研究提供了一种可行的研究方法。 Increasing data have been accumulated for the existence and manifestation of radiation induced bystander effects (RIBE) in the wholeorganism context. However,the early signaling in RIBE in vivo has been unclear due to the lack of relevant methodology. In the present study,a novel plant experimental system for studying the early signaling in RIBE in vivo was established, in which the expression level of HR related AtRAD54 gene was measured as a biological endpoint,and the root cutting and grafting were used to stop and restore the signaling communication from irradiated roots to bystander aerial plants.
成都金沙遗址古代陶片的PIXE和RBS分析(英文)
叶沥, 刘慢天, 黄伟, 杨盛, 安竹, #
2010, 27(4): 493-499. doi: 10.11804/NuclPhysRev.27.04.493
摘要:
成都金沙遗址的年代覆盖了商代晚期至西周时期(公元前1200年—公元前650年), 一般被认为是三星堆文化的延续。初步建立了质子激发X射线发射(PIXE)和卢瑟福背散射(RBS)实验装置, 并采用PIXE和RBS方法研究了从金沙遗址出土的部分陶片的元素组成。通过因子分析, 观察到来自不同地层的陶片的元素组成存在一定的差异, 这可能意味着制作陶器的陶土在不同时期取自不同的地点。也观察到来自不同发掘坑的陶片的元素组成没有明显的聚类现象, 这可能意味着制作不同使用用途的陶器所用的陶土是没有区别的。Jinsha Ruins Site, Chengdu, China, spanned the age from late Shang Dynasty to Western Zhou Dynasty (B.C.1200—B.C.650), was generally considered as the inheritance of Sanxingdui Culture. This paper focuses on the studies of the pottery unearthed from Jinsha. PIXE and RBS experimental setup was preliminarily established and these techniques were employed to find the elemental composition of those collected shards. From the results of factor analysis, the differences can be seen among pottery shards from different stratums, which may suggest that the clay gathered from different sites was used in different periods. The authors also found that there was no obvious assemblage phenomenon in the factor analysis among the pottery shards from different pits, this may be the evidence for “no special clay for special use”.
低能He2+与He原子碰撞转移电离出射电子能谱研究
冯文天, 马新文, #, 朱小龙, 张少峰, 刘惠萍, 李斌, 闫顺成
2010, 27(4): 500-504. doi: 10.11804/NuclPhysRev.27.04.500
摘要:
利用反应显微成像谱仪对70和100 keV He2+与He原子碰撞转移电离(TI)过程中不同出射角度的电子能谱进行了测量,观测到出射电子能谱具有如下分布特征: 出射电子速度分布介于0和入射离子速度vp之间;在不同出射角度电子能谱分布均有一极大值存在, 随着出射角度的增大, 能谱分布极大值逐渐减小; 当电子出射角度等于45°时,多数电子集中在0 eV附近。 上述特征可由低能离子原子碰撞“准分子”模型进行定性解释。在100 keV He2+He转移电离出射电子能谱中有靶电子被俘获至散射离子连续态(electron capture to continuum, 简称ECC)电子的贡献, 这可看做是动力学两步过程的作用。 The energy spectra of emitted electrons in transfer ionization process of 70 and 100 keV He2+ colliding on He haev been measured by using Reaction Microscope . The energy spectra of the ejected electrons have been obtained in the angular range from 0° to 45° and energies from 0 to 45 eV. The characteristics of the energy spectra were analyzed. There is a maximum in each energy spectrum related to different emission angles; The position of the maximum decreases with increasing the emission angle; The velocity of emitted electrons is between 0 and vp, where vp is the projectile velocity; Most electrons are around 0 eV when electron emission angle is 45°. These characteristic could be qualitatively explained in a “quasimolecule” model. The ECC electrons were observed in the transfer ionization process of 100 keV He2+ colliding on He collision, It could be explained as dynamical twostep process.
Ne原子(e,2e)反应中反冲离子动量分析
张鹏举, 马新文, #, 闫顺成, 许慎跃, 张少峰, 朱小龙, 刘惠萍
2010, 27(4): 505-509. doi: 10.11804/NuclPhysRev.27.04.505
摘要:
利用冷靶反冲离子动量谱仪,对电子轰击Ne原子的单电离反应(e,2e)进行了研究,实验测量了70—3300 eV入射能量情况下,反应过程中产生的一价反冲离子的动量分布,并对反冲离子的总动量进行了还原。介绍了一个简单的碰撞机制, 据此着重分析了反冲离子纵向动量和横向动量二维谱形成的原因,该碰撞机制能够较好地解释较高能量入射时的实验结果。 最后根据反冲离子的动量,估算了出射电子的能量范围, 为下一步进行电子、离子的符合测量奠定了基础。 Using cold target recoilion momentum spectroscopy(COLTRIMS) we have measured the momenta of recoil target ions in the single ionization(e, 2e) reactions of Ne at the energies between 70 and 3300 eV. A simple collision mechanism was introduced to analyze the distributions of the momenta of recoil ions. This mechanism can qualitatively well explain the distributions for the intermediate and high impact energy. Finally,the energy range of the ionized electron according to the momenta of the ion was estimated,which lays the foundation for the next coincidence measurement of electrons and ions.