HIRFL-CSR实验环团簇内靶的首批测试实验

内靶装置是兰州重离子冷却储存环(HIRFL-CSR)实验环的一个重要的插入件,也是世界上第一个嵌入在重离子储存环中的内靶装置,它位于HIRFL-CSR实验环的一个直线段.团簇内靶具有传统外靶所不具备的一些优点,如高亮度、高精度和高灵敏度等.这些优点可使我们在内靶实验平台上进行一些高精度的物理实验.为满足不同物理实验的需求,内靶可以有两种工作模式:非极化靶运行模式和极化靶运行模式,用于为实验环内的物理实验提供厚度为1011~1013atoms/cm2的非极化靶和极化靶.团簇靶是属于非极化靶运行模式,它采用超声喷气和冷凝相结合的方法获得团簇粒子束,并在碰撞靶室中与环内束流相碰撞,未反应的团簇束被收集级抽走.团簇内靶可以提供靶密度约为2×1013atoms/cm2的Ne、Ar、Kr、Xe和N2、CH4等团簇束.目前已完成了团簇靶的现场安装和准直,并进行了真空达标、喷嘴冷却和稳定性等首批测试实验.本文主要介绍团簇靶的工作原理和首批测试实验结果.

用于高电荷态离子与表面相互作用研究的原子物理实验平台

在重离子加速器国家实验室ECR离子源上,成功组建了用于高电荷态离子与表面相互作用研究的原子物理实验平台;利用该实验平台,研究了用不同电荷态和不同速度的高电荷态离子与不同表面相互作用的可见光和X射线发射的情况,同时还研究了高电荷态Xe离子轰击晶体材料所引起的材料性质和表面结构变化的情况.

热峰模型在聚碳酸酯非晶化潜径迹中的应用

为了描述快重离子在聚合物中的潜径迹行为 ,用不同能量的快重离子 (1 15 8GeVFe56 ,1 75 5GeVXe1 36 及 2 6 36GeVU2 38)辐照叠层半结晶聚碳酸酯膜 (MakrofolKG型 ) ,结合x射线衍射测量技术 ,在较宽的电子能损 (1 9— 17 1keV nm)和离子注量 (5× 10 1 0 — 3× 10 1 2 cm- 2 )范围研究了离子在半结晶聚碳酸酯中引起的非晶化过程 .应用径迹饱和模型假设 (损伤过程只发生在面积为σ的柱形径迹内 ) ,分别给出了Fe,Xe和U离子在不同电子能损下辐照聚碳酸酯时的平均非晶化径迹半径 .用热峰模型对实验结果进行了检验 ,结果表明Szenes的热峰模型较好地描述了离子在聚合物中的潜径迹行为 .

提高在线同位素分离器分离效率的实验研究

描述了兰州在线同位素分离器的最新进展 .利用FEBIAD离子源 (受迫电子引起的弧放电源 )开展了中、低能在线实验 .在线同位素分离器的质量分辨本领达到 50 0— 70 0 ;Kr和Xe的离线分离总效率分别达到 3 1 %和 4 5% ;10 4In ,　10 4Ag,10 4Gd的在线分离总效率达到 1 %— 2 % ;Hg的在线分离总效率达到 5% .成功地实现了对In ,Ag,Gd ,Hg ,Rn ,At等一系列元素的同位素分离 .

FEBIAD离子源的新进展

描述了用于兰州在线同位素分离的FEBIAD靶 -离子源的改进、最新进展和结果。经过改进后 ,在线同位素分离器对Xe的分辨本领由原来的 360提高到 60 0 ,对199Hg的在线测量效率提高了一个数量级 ,并测出了Hg、At、Rn等元素的一系列放射性同位素产物及生成截面为 5×10 - 34 m2 的2 0 8Hg衰变的能量最高的一条γ线。

兰州在线同位素分离器的FEBIAD源研制

叙述了兰州近代物理研究所的在线同位素分离器FEBIAD源的设计原理、结构、运行状况及离线和在线调试结果。离线测定Kr和Xe的总效率分别为 3.1%和 4 .5% ,12 9Xe分辨本领达到36 0 ,离子源总离子束流小于 10 μA。在线测到截面为 10 - 2 8cm2 、寿命短至 1s的反应产物 ,在线测出10 4 In总效率达到 1.5%— 2 % ,10 4 Ag和10 4 Gd达到 1%。

An outlook of heavy ion driven plasma research at IMP-Lanzhou

Since the successful completion of the cooling storage ring (CSR) project in China at the end of 2007, high qualitative heavy ion beams with energy ranging from keV to GeV/u have been available at the Heavy Ion Research Facility at Lanzhou (HIRFL). More than 10(9) 1 GeVlu C6+ particles or 10(8) 235 MeV/u Xe particles can be stored in the CSR main-ring and extracted within hundred nano-seconds during the test running, the beam parameters will be improved in the coming years so that high energy density (HED) conditions could be achieved and investigated there. Recent scientific results from the experiments relevant to plasma research on HIRFL are summarized. Dense plasma research with intense heavy ion beams of CSR is proposed here.

高电荷态离子126Xeq+引起GaN表面形貌变化研究

用不同电荷态的126Xeq+离子（9≤q≤30）在室温下轰击GaN晶体表面，经原子力显微镜分析表明，当q>18，辐照区域由隆起转为显著的刻蚀.被轰击后的GaN晶体表面形貌主要取决于入射离子的电荷态.同时，样品表面形貌还与入射离子的剂量和入射角有关；在实验参数范围，与入射离子的初动能没有明显关系（180 keV≤Ek≤600 keV）.当入射离子的电荷态q=18，与样品表面法线成60°角倾斜入射和垂直表面入射时，样品的表面几乎没有变化，只是倾斜入射后有很微小的隆起；当q＜18时，样品表面膨胀隆起，粗糙度增强，倾斜入射时表面隆起比垂直入射时更明显，而且都有清晰的峰状分界区；当q＞18时，样品表面被蚀刻呈凹陷状，有明显的齿状刻痕，且侵蚀深度与离子剂量近似呈线性关系，倾斜入射时的刻蚀深度大于垂直入射时的刻蚀深度.

HIRFL-CSR complex

The construction and commissioning of HIRFL-CSR were finished in 2007. From 2000 to 2005 the subsystem and key devices of CSR were successfully fabricated, such as magnet, power supply, UHV system, e-cooler, electric-static deflector with the septum of 0.1 mm, and the fast-pulse kicker with the rise time of 150 ns. After that the CSR commissioning activities were performed in 2006 and 2007, including the accumulation of those heavy ions of C, Ar, Kr and Xe by the combination of stripping injection (STI) or multiple multi-turn injection (MMI) and e-cooling with a hollow e-beam, wide energy-range synchrotron ramping by changing the RF harmonic-number at mid-energy, the beam stacking in the experimental ring CSRe, the RIBs mass-measurement with the isochronous-mode in CSRe by using the time-of-flight method, and the ion beam slow-extraction from CSRm.

Rapid detection of porcine circovirus type 2 by loop-mediated isothermal amplification

A method of loop-mediated isothermal amplification (LAMP) was employed to develop a rapid and simple detection system for porcine circovirus type 2 (PCV2). The amplification could be finished in 60 min under isothermal condition at 64 degrees C by employing a set of four primers targeting the cap gene of PCV2. The LAMP assay showed higher sensitivity than the conventional PCR, with a detection limit of five copies per tube of purified PCV2 genomic DNA. No cross-reactivity was observed from the samples of other related viruses including porcine circovirus type 1 (PCV1), porcine parvovirus (PPV), porcine pseudorabies virus (PRV) and porcine reproductive and respiratory syndrome virus (PRRSV). The detection rate of PCV2 LAMP for 86 clinical samples was 96.5% and appeared greater than that of the PCR method. The LAMP assay reported can provide a rapid yet simple test of PCV2 suitable for laboratory diagnosis and pen-side detection due to ease of operation and the requirement of only a regular water bath or heat block for the reaction. (c) 2008 Elsevier B.V. All rights reserved.

HIRFL today

HIRFL was upgraded from beginning 2000. Besides of researches on nuclear physics, atomic physics, irradiative material and biology, the cancer therapy by heavy ion and hadron physics are being developing. The injector system of SFC+SSC can provide all ions from proton to uranium with higher intensity. The Cooling Storage Ring (CSR) has accelerated beams successful. The ions C-12(6+), Ar-36(18+), Xe-129(27+) have been accelerated up 1000MeV/u, 235MeV/u with about 10(9)similar to 10(8) ions per spill respectively. The beam momentum dispersion was measured from 4x10(-3) to 2x10(-4) after cooling by the electron cooler or similar to 4x10(-4) after accelerated to 1000MeV/u without cooling. In order to improve the nuclear structure and heavy isotope research in SFC+SSC energy domain, A Wien filter was added in front of RIBLL and gas was filled in first section of RIBLL; a new spectrometry SHANS has being installed. Presently, there are two starting version experimental setups at CSR.

Theoretical analysis of xuv photoabsorption spectra of laser-produced iodine plasmas

The 4d photoabsorption spectra of I2+, I3+, and I4+ have been obtained in the 70-127 eV region with the dual laser-produced plasma technique at time delays ranging from 400 to 520 ns. With decreasing time delay, the dominant contribution to the spectra evolves from the I2+ to the I4+ ions, and each spectrum contains discrete 4d-nf transitions and a broad 4d-epsilon f shape resonance, which are identified with the aid of multiconfiguration Hartree-Fock calculations. The excited states decay by direct autoionization involving 5s or 5p electrons, and rates for the different processes and resulting linewidths were calculated. With increasing ionization, the 4d-epsilon f shape resonance become intense and broader in going from I2+ to I3+, and then vanishes at I5+. In addition, the discrete structure of the calculated spectrum of each ion gradually approaches the corresponding shape resonance position. Based on the assumption of a normalized Boltzmann distribution among the excited states and a steady-state collisional-radiative model, we reproduced spectra which are in good agreement with experiment.

X-ray emission of hollow atoms formed by highly charged argon and xenon ions below a beryllium surface

The X-ray emission induced by highly charged argon and xenon ions impinging on a beryllium surface is investigated. It is found that spectra of the X-ray induced by Ar-17,Ar-18+ interacting with the surface are very different from those of the X-ray induced by Ar-17,Ar-18+ interacting with residual gases. The result provides an experimental evidence for the existence of hollow atoms below the surface. Several unexpected X-ray lines are also found in the experiment. Firstly, K X-rays are observed when Ar16+ ions which initially have no K shell holes interact with the surface. Secondly, if there are more than 2 M shell vacancies at the initial time, strong M alpha alpha two-electron-one-photon (TEOP) transitions are found in the collisions of Xe-28+,Xe-29+,Xe-30+ ions with the surface.

Structural modification of C-doped SiO2 induced by swift heavy ion irradiations

Thermally grown amorphous SiO2 samples were implanted at room temperature (RT) with 120 keV C-ions to a dose ranging from 1.0 x 10(16) to 8.6 x 10(17)C ions/cm(2), then irradiated at RT with 950 MeV Pb, 345 or 1754 MeV Xe ions to a fluence in the region from 1.0 x 10(11) to 3.8 x 10(12) ions/cm(2), respectively. The irradiated samples were investigated using micro-FTIR and micro-Raman spectroscopes. It was found that new chemical bonds such as Si-C, C=C(O), C C and Si(C)-O-C bonds formed significantly in the C-doped SiO2 films after heavy ion irradiations. The evolution of Si-O-C bonds and possible mechanism of structural modification in C-doped SiO2 induced by swift heavy ion irradiations were discussed.

Color center formation in alpha-Al2O3 induced by high energy heavy ions

Single crystals of alpha-alumina were irradiated at room temperature with 1.157 (GeVFe)-Fe-56, 1.755 (GeVXe)-Xe-136 and 2.636 (GeVU)-U-238 ions to fluences range from 8.7 x 10(9) to 6 x 10(12) ions/cm(2). Virgin and irradiated samples were investigated by ultraviolet visible absorption measurements. The investigation reveals the presence of various color centers (F, F+, F-2(2+), F-2(+) and F-2 centers) appearing in the irradiated samples. It is found that the ratio of peak absorbance of F-2 to F centers increases with the increase of the atomic numbers of the incident ions from Fe, Xe to U ions, so do the absorbance ratio of F-2(2+) to F+ centers and of large defect cluster to F centers, indicating that larger defect clusters are preferred to be produced under heavier ion irradiation. Largest color center production cross-section was found for the U ion irradiation. The number density of single anion vacancy scales better with the energy deposition through processes of nuclear stopping, indicating that the nuclear energy loss processes determines the production of F-type defects in heavy ion irradiated alpha-alumina.