Inactive and mutagenic effects induced by carbon beams of different LET values in a red yeast strain

To evaluate biological action of microorganism exposed to charged particles during the long distance space exploration. Induction of inactivation and mutation in a red yeast strain Rhodotorula glutinis AY 91015 by carbon beams of different LET values (14.9-120 0 keV mu m(-1)) was investigated It was found that survival curves were exponential, and mutation curves were linear for all LET values The dependence of inactivation cross section on LET approached saturation near 120 0 keV mu m(-1) The imitation cross section saturated when LET was higher than 582 keV mu m(-1) Meanwhile, the highest RBEI for inactivation located at 120 0 key mu m(-1) and the highest RBEm for mutation was at 58.2 key mu m(-1) The experiments imply that the most efficient mutagenic part of the depth dose profile of carbon ion is at the plateau region with intermediate LET value in which energy deposited is high enough to Induce mutagenic lesions but too low to induce over kill effect in the yeast cells (C) 2010 Elsevier B V All rights reserved

CSR ns级重离子束动力学研究；Dynamics Study of Attaining Heavy Ion Beam With a Scale of Nanosecond Pulse Length in CSR

采用束团在纵向相空间快速旋转的非绝热压缩方法研究了在兰州重离子加速器冷却储存环(HIRFL-CSR)上获取高能ns量级短脉冲重离子束的可行性,利用K-V包络方程对能量为250MeV/u、初始纵向束团长度为200ns、初始动量分散为5×10-4的238U72+离子束团的非绝热压缩过程进行了束流动力学模拟,给出了在束团压缩过程中束流相关参数的变化。结果表明,在CSR上可取得最短为16ns长度的238U72+离子束团,可满足用于高能量密度物理研究的50ns束团长度的要求。

Color center formation in silica glass induced by high energy Fe and Xe ions

Silica glass samples were implanted with 1.157 GeV Fe-56 and 1.755 GeV Xe-136 ions to fluences range from 1 x 10(11) to 3.8 x 10(12) ions/cm(2). Virgin and irradiated samples were investigated by ultraviolet (UV) absorption from 3 to 6.4 eV and photoluminescence (PL) spectroscopy. The UV absorption investigation reveals the presence of various color centers (E' center, non-bridging oxygen hole center (NBOHC) and ODC(II)) appearing in the irradiated samples. It is found that the concentration of all color centers increase with the increase of fluence and tend to saturation at high fluence. Furthermore the concentration of E' center and that of NBOHC is approximately equal and both scale better with the energy deposition through processes of electronic stopping, indicating that E' center and NBOHC are mainly produced simultaneously from the scission of strained Si-O-Si bond by electronic excitation effects in heavy ion irradiated silica glass. The PL measurement shows three emissions peaked at about 4.28 eV (alpha band), 3.2 eV (beta band) and 2.67 eV (gamma band) when excited at 5 eV. The intensities of alpha and gamma bands increase with the increase of fluence and tend to saturation at high fluence. The intensity of beta band is at its maximum in virgin silica glass and it is reduced on increasing the ions fluence. It is further confirmed that nuclear energy loss processes determine the production of alpha and gamma bands and electronic energy loss processes determine the bleaching of beta band in heavy ion irradiated silica glass. (c) 2009 Elsevier B.V. All rights reserved.

Alpha-decay for heavy nuclei in the ground and isomeric states

The alpha-decay half-lives of nuclei in the ground states and Isomeric states have been calculated within the WKB approximation and Royer's formulas. The barrier in the quasimolecular shape path is determined within a generalized liquid drop model (GLDM). in which the centrifugal potential energy has been introduced to study the unfavored a-decay The agreement between the calculated results and experimental data indicates the reliability of studying alpha-decay of isomeric states with the generalized liquid drop model We find that their is no significant difference of preformation probability between Isomeric states and the corresponding ground states generally in favored alpha-decay Additionally. we extended Royer's formulas by taking account of the role of centrifugal harrier to study the unfavored alpha-decay, and some predicts oil the a decay half-lives of Isomers are made Finally. the effects of angular momontum transfer and Q(alpha) on alpha-decay half-life have been discussed Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved

Preliminary study of a niobium quarter-wave prototype cavity for a heavy-ion superconducting linac

Superconducting quarter-wave resonators, due to their compactness and their convenient shape for tuning and coupling, are very attractive for low-beta beam acceleration. In this paper, two types of cavities with different geometry have been numerically simulated: the first type with larger capacitive load in the beam line and the second type of lollipop-shape for 100 MHz, beta=0.06 beams; then the relative electromagnetic parameters and geometric sizes have been compared. It is found that the second type, whose structural design is optimized with the conical stem and shaping drift-tube, can support the better accelerating performance. At the end of the paper, some structural deformation effects on frequency shifts and appropriate solutions have been discussed.

Ultrahigh compression of water using intense heavy ion beams: laboratory planetary physics

Intense heavy ion beams offer a unique tool for generating samples of high energy density matter with extreme conditions of density and pressure that are believed to exist in the interiors of giant planets. An international accelerator facility named FAIR (Facility for Antiprotons and Ion Research) is being constructed at Darmstadt, which will be completed around the year 2015. It is expected that this accelerator facility will deliver a bunched uranium beam with an intensity of 5x10(11) ions per spill with a bunch length of 50-100 ns. An experiment named LAPLAS (Laboratory Planetary Sciences) has been proposed to achieve a low-entropy compression of a sample material like hydrogen or water (which are believed to be abundant in giant planets) that is imploded in a multi-layered target by the ion beam. Detailed numerical simulations have shown that using parameters of the heavy ion beam that will be available at FAIR, one can generate physical conditions that have been predicted to exist in the interior of giant planets. In the present paper, we report simulations of compression of water that show that one can generate a plasma phase as well as a superionic phase of water in the LAPLAS experiments.

Finding a Probe for Extracting Information on the Momentum Dependent-Interaction in Heavy Ion Collisions

The effect of momentum-dependent interaction on the kinetic energy spectrum of the neutron-proton ratio. <(n/p)(gas)>(b)(E-k) for Zn-64 + Zn-64 is studied. It is found that. <(n/p)(gas)>(b)(E-k) sensitively depends on the momentum-dependent interaction and weakly on the in- medium nucleon- nucleon cross section and symmetry potential. Therefore <(n/p)(gas)>(b)(E-k) is a possible probe for extracting information on the momentum-dependent interaction in heavy ion collisions.

~(12)C~(6+)高能重离子辐照大葱损伤及其分子生物学效应；Cytological Damage and Molecular Biology Effect of ~(12)C~(6+) Heavy Ions on Allium fistulosum L.

利用30,90,180Gy3种剂量的12C6+重离子束辐照大葱种子,研究其在细胞水平和农艺性状的诱变效应并进行RAPD分析。通过与M1代的研究结果比较后表明:经过不同剂量12C6+重离子照射后能有效地诱导大葱细胞形成微核和染色体畸变,这种诱变效应,在M2代仍然有所表现。M1代大葱结果期的株高、白长、花序直径和种子产量随辐照剂量增加产生明显差别,其中30Gy辐照组增幅最大。大葱总水溶性蛋白质和维生素C的含量在30Gy组中积累最多,在90Gy组有明显下降。与M1代一致,M2代中大葱染色体微核率及RAPD分析所得的DNA多态性比率仍然与辐照剂量呈正相关,但比率整体下降;说明高能量重离子辐照造成的DNA变异在M2代被修复和淘汰。

PROPERTIES OF ALPHA DECAY TO ROTATIONAL BANDS OF HEAVY NUCLEI

In the framework of the generalized liquid drop model (GLDM) and improved Royer's formula, we investigate the branching ratios and half-lives of alpha-decay to the members of the ground-state rotational bands of heavy even-even Fm and No isotopes. The calculated results are in good agreement with the available experimental data and some useful predictions are provided for future experiments.

PROBING THE SYMMETRY ENERGY AT SUPRA-SATURATION DENSITIES FROM PION EMISSION IN HEAVY-ION COLLISIONS

Within the framework of the improved isospin dependent quantum molecular dynamics (ImIQMD) model, the emission of pion in heavy-ion collisions in the region 1 A GeV as a probe of nuclear symmetry energy at supra-saturation densities is investigated systematically, in which the pion is considered to be mainly produced by the decay of resonances Delta(1232) and N*(1440). The pi(-)/pi(+) yields are calculated for selected Skyrme parameters SkP, SLy6, Ska and SIII, and also for the cases of different stiffness of symmetry energy with the parameter SLy6. Preliminary results compared with the measured data by the FOPI collaboration favor a hard symmetry energy of the potential term proportional to (rho/rho(0))(gamma s) with gamma(s) = 2.

尖晶石中He离子辐照缺陷的演化及其对重金属原子的俘获效应研究

本项工作利用多种分析手段（FTIR、TDS、RBS/C、AFM、SEM），对100keV He离子不同剂量（0.5，2.0，8.0×1016cm-2）注入的尖晶石中缺陷的形成及其对重金属原子的俘获效应进行了研究。在FTIR谱上观察到了Al-O键的共振吸收峰随剂量增加向小波数方向移动和随退火温度升高向大波数方向回复；随退火温度增加这三组样品的晶格损伤均经历先增大后减小的过程，但随剂量不同晶格损伤开始增加的温度不同；注入剂量为2.0×1016 cm-2样品在退火过程中其表面发生了形变，随剂量增加样品表面发现起皮现象。上述差异被认为是样品中不同缺陷的形成所引起的。随后，尝试了利用He离子注入形成的空位型缺陷俘获重金属原子的方法在尖晶石中合成金属纳米颗粒。吸收光谱上SPR吸收峰的出现，证实了金属纳米颗粒的形成

Trends in heavy metal levels in the dissolved and particulate phase in the Dutch rhine-meuse (MAAS) delta*

Levels of the heavy metals Cd, Cr, Cu, Pb and Zn, in both the dissolved and particulate phase, were determined in two sampling campaigns in August 1978 and August 1984 in the Dutch Rhine-Meuse (Maas) Delta. Besides the heavy metal concentrations, other important parameters were determined, such as the concentrations of seston, chlorophyll and nutrients. The concentrations of dissolved Cd and of Cd, Pb and Cu in particulate matter were much higher in 1978 than in 1984, especially for Cd. This may be due to the strict regulations implemented in Germany to reduce the pollution of natural waters by heavy metals. The correlation between the high Cd content and the chlorophyll content is explained by the binding of Cd to living and dead organisms. The distribution of the metals between the dissolved and the particulate phase, indicated by the distribution quotient Kd , increases from low values of Kd for Cu and Zn, to higher values for Cd and Cr, and the highest values for Pb. The differences are explained by various binding forms of each of these metals in natural waters

Heavy Metals in Soil and Crops of an Intensively Farmed Area: A Case Study in Yucheng City, Shandong Province, China

lThe study was supported by the Knowledge Innovation Foundation of the institute of Geographical Sciences and Natural Resource, Chinese Academy of Sciences (Grant No. 200906002) and Key Directional Project of Knowledge Innovation of Chinese Academy of Sciences (Grant No. KSCX2-YW-N-46-01). The authors would like to thank to Luke Driskell for his kind help and hard work on English language polishing of the article.