Ionization Scheme Development at the ISOLDE RILIS

The resonance ionization laser ion source (RILIS) of the ISOLDE on-line isotope separation facility is based on the method of laser step-wise resonance ionization of atoms in a hot metal cavity. The atomic selectivity of the RILIS complements the mass selection process of the ISOLDE separator magnets to provide beams of a chosen isotope with greatly reduced isobaric contamination. Using a system of dye lasers pumped by copper vapour lasers, ion beams of 24 elements have been generated at ISOLDE with ionization efficiencies in the range of 0.5–15%. As part of the ongoing RILIS development off-line resonance ionization spectroscopy studies carried out in 2003 and 2004 have determined the optimal three-step ionization schemes for scandium, antimony, dysprosium and yttrium.     

Depollution of uranyl polluted waters using pillared clays

This paper reports on the use of clays pillared with copper polyhydroxycations in the depollution of waters polluted with radioactive elements. The pillared clays have very good surface properties which recommend them for use in cationic depollution. The article includes a kinetic study on the depollution of radioactive polluted waters, studying the influence of temperature on the process. The pillared clays are prepared from Romanian clay originally from Valea Chioarului deposits; the experiments have used an autochthonous material in an unconventional performant depollution technology.     

Simulation and analysis of 13N+p elastic resonance scattering

The 13N+p elastic resonance scattering has been studied at the secondary radioactive beam facility of CIAE in inverse kinematics via a thick-target method. The excitation function for the 13N(p,p) scattering was obtained in the energy interval of Ecm ≈0.5--3.2 MeV with a 13N secondary beam of (47.8±1.5) MeV. Carefulanalysis of the secondary beam components and extensive Monte-Carlo simulations enable the resolution of the experimental proton spectra. The resonance parameters for five low-lying levels in 140 were deduced by R- matrix fitting calculations with MULTI7 and SAMMY-M6-BETA. The present results show general agreement with those from a recent similar work, and thus confirm the observation of a new 0- level at 5.7 MeV in 14O with an improved width of 400(45) keV.     

Probing the nuclear symmetry energy with heavy-ion reactions induced by neutron-rich nuclei

Heavy-ion reactions induced by neutron-rich nuclei provide a unique means to investigate the equation of state of isospin-asymmetric nuclear matter, especially the density dependence of the nuclear symmetry energy. In particular, recent analyses of the isospin diffusion data in heavy-ion reactions have already put a stringent constraint on the nuclear symmetry energy around the nuclear matter saturation density. We review this exciting result and discuss its implications on nuclear effective interactions and the neutron skin thickness of heavy nuclei. In addition, we also review the theoretical progress on probing the high density behaviors of the nuclear symmetry energy in heavy-ion reactions induced by high energy radioactive beams.      

Nuclear physics with simple and multi-element detectors and with stable and radioactive beams

The phenomenon of fusion barrier distributions is discussed in the context of a problem already investigated in some detail with simple detection systems, but possessing avenues to studies with multi-detector arrays. The complementarity of research with simple and complex detectors, as well as with stable and radioactive beams, will be highlighted.     

28.7MeV/u的 14，16，18 O+7，9Be反应中的同位素分布研究

用同位旋相关的Boltzmann-Langevin方程研究了在入射能量为28.7MeV/u下,不同弹核^14O,^16O和^18O轰击不同靶核^7Be和^9Be的反应,计算了生成碎片的产生截面,发现用丰中子（缺中子）炮弹或丰中子（缺中子）靶进行反应,所得到的产物均有丰中子（缺中子）的碎片出现。同位素分布宽度和峰位与入射体系密切相关,产生碎片的电荷数越接近入射弹核的电荷数,则同位素分布的宽度越大,峰位偏离β稳定线值越远,其同位旋效应越明显。。     

兰州重离子加速器的状态和发展

文章首先简要地介绍了世界上重离子加速器的发展状态,然后对兰州重离子加速器（HRFL）的结构,建造过程,运行情况,多年来以及目前正在进行的主要改造项目进行了描述,为适应核物理及其相关学科的持续发展研究的需要,对HIRFL近期和将来的发展情况作了概括的描述。     

Accurate Mass Determination of Neutron-Deficient Nuclides Close to Z=82 with ISOLTRAP

The recent implementation of gas-filled radiofrequency traps for efficient ion beam bunching extended the applicability of the Penning trap mass spectrometer ISOLTRAP/CERN to non-surface ionizable species. In a first series of successful runs the masses of ^182–197Hg, ^196,198Pb, ¹⁹⁷Bi, ¹⁹⁸Po and ²⁰³At have been determined with an accuracy of 1⋅10⁻⁷. In order to unambiguously determine the ground state mass the ground and isomeric states of ^{185,187,191,193,197}Hg were separated applying a resolving power of up to 3.7⋅10⁶. First experimental values for the isomeric excitation energy of ^187,191Hg were obtained. This revised version was published online in July 2006 with corrections to the Cover Date.     

Improvement of the Applicability, Efficiency, andPrecision of the Penning Trap Mass Spectrometer ISOLTRAP

With the Penning trap mass spectrometer ISOLTRAP, close to 200 nuclides have already been investigated and their masses determined with a typical relative precision of δm/m=10⁻⁷. Recently, ISOLTRAP's beam preparation system was replaced by an RFQ ion beam cooler and buncher. The principle and the characteristics of this new beam preparation system will be presented. It is planned to use ions of various carbon clusters C⁺ _n (n>1) as reference ions for mass measurements. Apart from negligible molecular binding energies, these clusters have masses that are exact multiples of the unified atomic mass unit. This will allow ISOLTRAP to carry out absolute mass measurements as well as to investigate possible mass-dependent systematic errors. The results of tests of the production, transport, and trapping of such carbon clusters will be presented. This revised version was published online in July 2006 with corrections to the Cover Date.     

地下玻璃固化体中元素垂直迁移规律初探

利用上升气流模型模拟研究了地下玻璃固化体中As, Cs和Sr元素的迁移行为。 利用中子活化分析（INAA）技术检测了玻璃固化体中元素迁出量, 用原子力显微镜观察了迁出物质的形态。 实验结果表明: 在上升气流作用下, 被玻璃固化的元素会以纳米微粒的形式迁移出来, 迁移方向是垂直向上的, 迁出的元素会在玻璃固化体上方的吸附物中不断积累; 上升气流作用时间越长, 固化体中元素迁出的量越大; 玻璃固化体处置点与地表的温差越大, 元素迁出的速度越快。 The transporting behavior of As, Cs, Sr in vitrification form has been studied using a simulating model of ascending flows.Instrumental Neutron Activation Analysis (INAA) was used to determine the quantity of elements transportation. The results of simulating experiment show that the elements can be transported vertically from the vitrification form by ascending flows in the form of nano scale particles. Then these elements accumulate continuously in the adsorber above the vitrification form. In addition, when the temperature difference between the ground surface and the environment where the vitrification form disposed increases, the transportation speed of these elements will increase too.