Survival and initial chromatid breakage in normal and tumour cells exposed in vitro to gamma rays and carbon ions at the HIRFL

Human hepatoma and normal liver cells were irradiated with C-12(6+) ion beams (linear energy transfer (LET) = 96 keV mu m(-1)) and gamma-rays at the Heavy Ion Research Facility in Lanzhou (HIRFL). The numbers and types of chromatid breaks were detected using the premature chromosome condensation technique. Irradiation with C-12(6+) ions produced a majority of isochromatid break types, while chromatid breaks were dominant for irradiation with gamma-rays. Experimental results showed that the initial level of chromatid breaks is clearly related to the absorbed dose from C-12(6+), ions and gamma-rays. The (12)C(6+)ions are relatively more effective at inducing initial chromatid breaks when compared with the gamma-rays. A relative biological effectiveness (RBE) of about 2.5 resulted for the induction of initial chromatid breaks by C-12(6+) ions relative to gamma-rays in both cell lines.

General design of the CSR project in IMP

CSR, a new accelerator project under the construction. to upgrade the existing heavy ion cyclotron system in Lanzhou, is a double cooling-storage-ring system. It consists of a main ring and an experimental ring. The heavy ion beams from the cyclotron system will be accumulated and accelerated first in the main ring, then extracted to produce radioactive ion beams or high-Z beams, and finally to be send to the second ring for internal-target experiments.

Materials research with swift heavy ions at the IMP accelerators

The main ion beams acceleration facilities and research fields of the Institute of Modern Physics (IMP) are briefly introduced. Some of the experimental instruments, typical works and the obtained results on the materials research with swift heavy ions at the IMP-accelerators are presented.

COD by magnetic field in electron-cooling section and correction at CSR

Application of electron-cooling upgrades the quality of ion beams in the storage rings and brings new problems. The transverse magnetic field distorts the ion orbit while guiding the intense electron beam. The closed-orbit distortion should be and can be localized and controlled well inside the ring acceptance. This paper deals with the field in the e-cool section and concomitant COD of ion orbit and shows the correction scheme.

Effect of p53 on lung carcinoma cells irradiated by carbon ions or X-rays

The study is to investigate the feasibility and advantages of heavy ion beams on radiotherapy. The cellular cycle and apoptosis, cell reproductive death and p53 expression evaluated with flow cytometry, clonogenic survival assays and Western blot analysis were examined in lung carcinoma cells after exposure to 89.63 MeV/u carbon ion and 6 MV X-ray irradiations, respectively. The results showed that the number colonyforming assay of A549 was higher than that of H1299 cells in two radiation groups; A549 cellular cycle was arrested in G(2)/M in 12 It and the percentage of apoptosis ascended at each time point of carbon ion radiation with doses, the expression of p53 upregulated with doses exposed to X-ray or carbon ion. The cell number in G(2)/M of H1299 and apoptosis were increasing at all time points with doses in C-12(6+) ion irradiation group. The results suggested that the effects of carbon ions or X rays irradiation on lung carcinoma cells were different, C-12(6+) ion irradiation could have more effect on upregulating the expression of p53 than X-ray, and the upregulated expression of p53 might produce the cellular cycle G(2)/M arrested, apoptosis increasing; and p53 gene might affect the lung cancer cells radiosensitivity.

Study of a magnetic alloy-loaded RF cavity for bunch compression at the CSR

The Heavy Ion Research Facility and Cooling Storage Ring (HIRFL-CSR) accelerator in Lanzhou offers a unique possibility for the generation of high density and short pulse heavy ion beams by non-adiabatic bunch compression longitudinally, which is implemented by a fast jump of the RF-voltage amplitude. For this purpose, an RF cavity with high electric field gradient loaded with Magnetic Alloy cores has been developed. The results show that the resonant frequency range of the single-gap RF cavity is from 1.13 MHz to 1.42 MHz, and a maximum RF voltage of 40 kV with a total length of 100 cm can be obtained, which can be used to compress heavy ion beams of U-238(72+) with 250 MeV/u from the initial bunch length of 200 ns to 50 ns with the coaction of the two single-gap RF cavity mentioned above.

Nuclear physics program at HIRFL

With the commissioning of HIRFL-CSR, HIRFL can provide heavy ion beams with energy covering the range of several MeV/u to 1 GeV/u. In this talk, the experiments on nuclear physics at different energies to be carried out with different experimental setups at HIRFL will be introduced.

Some Superconducting Magnets at IMP

Some superconducting magnets research at IMP (Institute of Modern Physics, CAS, Lanzhou) will be described in this paper. Firstly, a superconducting electron cyclotron resonance ion source (SECRAL) was successfully built to produce intense beams of highly charged heavy ions for Heavy Ion Research Facility in Lanzhou (HIRFL). An innovation design of SECRAL is that the three axial solenoid coils are located inside of a sextupole bore in order to reduce the interaction forces between the sextupole coils and the solenoid coils. For 28 GHz operation, the magnet assembly can produce peak mirror fields on axis of 3.6 T at injection, 2.2 T at extraction, and a radial sextupole field of 2.0 T at plasma chamber wall. Some excellent results of ion beam intensity have been produced and SECRAL has been put into operation to provide highly charged ion beams for HIRFL since May 2007. Secondly, a super-ferric dipole prototype of FAIR Super-FRS is being built by FCG (FAIR China Group) in cooperation with GSI. Its superconducting coils and cryostat is made and tested in the Institute of Plasma Physics (IPP, Hefei), and it more 50 tons laminated yoke was made in IMP. This super-ferric dipole static magnetic field was measured in IMP, it reach to the design requirement, ramping field and other tests will be done in the future. Thirdly, a 3 T superconducting homogenous magnetic field solenoid with a 70 mm warm bore has been developed to calibrate Hall sensor, some testing results is reported. And a penning trap system called LPT (Lanzhou Penning Trap) is now being developed for precise mass measurements.

Prototype of the Superferric Dipoles for the Super-FRS of the FAIR-Project

The FAIR China Group (FCG), consisting of the Institute of Modern Physics (IMP Lanzhou), the Institute of Plasma Physics (ASIPP, Hefei) and the Institute of Electric Engineering (IEE, Beijing) developed and manufactured in cooperation with GSI, Germany a prototype of a superferric dipole for the Super-Fragment-Separator of the FAIR-project [1]. The dipole magnets of the separator will have a deflection radius of 12.5 m, a field up to 1.6 T, a gap of at least 170 mm and an effective length of more than 2 meters to bend ion beams with a rigidity from 2 T . m up to 20 T . m. The magnets operate at DC mode. These requirements led to a superferric design with a yoke weight of more than 50 tons and a maximum stored energy of more than 400 kJ. The principles of yoke, coil and cryostat construction will be presented. We will also show first results of tests and measurements realized at ASIPP and at IMP.

重离子束辐照对植物组织培养及转基因操作的影响

目的：建立重离子束辐照结合植物组织培养技术进行植物诱变的新方法，使用该方法率先开展植物组织细胞的传能线密度（LET）生物学效应的研究，尝试重离子束辐照结合农杆菌转染及质粒微注射法转基因操作。 材料与方法：采用兰州重离子研究装置(HIRFL)加速的碳离子束辐照非洲紫罗兰、丽格海棠、新几内亚凤仙以及紫花苜蓿的外植体，测定形态学指标，计算不同外植体的相对生物学效应（RBE）。以非洲紫罗兰叶片外植体为对象研究RBE随LET的变化关系。使用氖离子束辐照烟草叶片外植体结合农杆菌转染方法进行赤霉素4（GA4）基因转染实验；使用碳离子束辐照苜蓿愈伤组织结合质粒微注射方法进行β－葡萄糖苷酸酶（GUS）基因转染实验。 结果： 1. 不同剂量的936MeV的碳离子束和8MV的X射线辐照三种花卉及一种牧草的外植体后，基于存活率的RBE值分别为2.3、1.6、2.1和4.0； 2. LET值在31~151keV/μm区间的碳离子束辐照非洲紫罗兰叶片外植体。基于鲜重增殖（FWI）的RBE值随LET的增加而增加，151keV/μm时达到最高值6.7； 3. 烟草离体叶片外植体经过5Gy的1600MeV氖离子束辐照后进行农杆菌转基因操作，最终获得转染率为3.9%，单纯农杆菌转基因的转染效率为3.2%； 4. 20Gy的936MeV的碳离子束辐照苜蓿愈伤组织后结合组织表面pBI121质粒溶液微量注射处理后，获得GUS基因瞬间表达效率高达84.6%。 结论： 1. 不同花卉植物组织培养用外植体的辐照敏感性不同，本研究发现丽格海棠的辐射敏感性最高，其次是新几内亚凤仙，非洲紫罗兰的最不敏感； 2. 不同花卉植物外植体经离子束辐照诱变处理后，得到的再生植株突变类型不尽相同，主要包括叶的突变和茎的突变； 3. RBE的随LET的增大而增加可以归因于离子在生物体中能量沉积的增加，研究发现各生物学终止点受到损伤或者抑制的程度基本上是随着LET的增大而增大； 4. 通过离子束辐照结合植物组织培养方法最终获得了非洲紫罗兰叶绿素缺失突变体，该突变体通过植物组织培养技术能够稳定遗传； 5. 中能氖离子束辐照能够略微提高烟草农杆菌转基因的转化效率，辐照能够使再生植株花期提前； 6. 中能碳离子束辐照结合苜蓿愈伤组织表面微量注射质粒溶液法进行转基因操作能获得更高的基因转染效率

重离子束治癌相关生物学效应及机理研究

重离子束治癌是当今放射治疗中最科学、最先进、最有效的方法，是有代表性的高技术。目前仅有美、日、德实现了该技术，并已取得常规疗法难以实现的疗效。我国近年来开展了“重离子束治癌技术的基础研究”，其中，放射生物学及机理研究是重要内容。本论文从细胞、DNA分子、以及动物个体的三个不同层次上分别研究了重离子束治癌相关的生物学问题。在细胞研究方面。采用HeLa、B 16两种细胞分别研究了X一射线和重离子在水介质中入射的深度与相应细胞的存活率(1一失活率)，结果表明：X一射线对细胞的损伤随深度而逐渐衰减(或细胞存活随深度逐渐增加)，而重离子对细胞的损伤则为Bragg曲线(或细胞存活为倒Bragg曲线)。研究了25MeV／u ~(40)Ar~(14+)辐照人肝癌细胞SMMC一7721的微核及存活的动态变化，结果表明： 单次照射与分次照射的微核率随时间的变化规律在96h内没有明显区别，受照(单次、分次) 肝癌细胞的存活数随时间表现出衰减趋势，微核率与细胞存活数关系的动态变化为负相关性。研究了6MV X-射线和125．5keV／μm的重离子辐照B 1 6、V79细胞的2Gy存活率(SF2)，结果表明：B16和V79细胞的存活率(P<0．01)依赖于不同的辐射性质(X-射线、~(12)C离子)，其X-射线与~(12)C离子辐射这两种细胞的存活率之比分别为5．4和1．43，即~(12)C离子辐射增强了X-射线抗性细胞系的敏感性，从而显示了重离子治疗癌症的优势。研究了125．5keV／um的碳离子辐照小鼠黑色素瘤B16、人的宫颈癌HeLa、中国仓鼠肺V79、人的肝癌SMMC-7721四种细胞的相对生物学效率(RBE)，得．到了RBE依赖于细胞种类的关系、RBE随细胞存活水平的升高而增加的关系、以及当LET≥125．5keV／μm时，RBE随着LET的增大而变小的关系。在DNA分子研究方面。研究了125．5keV／μm~(12)C~(6+)辐照小鼠黑色素瘤B 16、中国仓鼠肺V79、人的宫颈癌HeLa、人的肝癌SMMC一7721细胞的灵敏度(由D50表示)、DNA双链断裂(DSB)和DNA双链断裂片段分布，结果表明：细胞敏感性与DNA双链断裂之间没有一致的关系，提出了细胞辐射敏感性的一种可能的分子机理，即DNA序列敏感性位点协同DNA双链断裂互补性机理。由此解释了四种细胞系的不同敏感性问题。在动物个体研究方面。研究了57．28MeV／u氧离子50Gy一次性局部照射对B16黑色素瘤小鼠肿瘤生长的抑制作用，并观测了受照小鼠的死亡情况，结果表明：照射B16黑色素瘤后第10天观察，肿瘤生长延迟为6天、肿瘤抑制率为66％，耐受剂量小于50Gy。研究了50MeV／u ~(12)C~(6+)离子辐照对小鼠移植性肿瘤S180的抑制作用、控制率、治愈率和病理组织学变化，结果表明：各剂量组对S180肉瘤的抑制作用均大于90％，高剂量组抑瘤作用明显强于低、中剂量组(P

重离子辐照普通小麦间接效应的研究

应用不同能量、不同剂量的碳离子和氧离子加照普通小麦，研究其M1代和M2代的生物学（形态）性状、染色体畸变率及微核率、生理生化和DNA分子等方面的变化。并对这些变化的生物学机理进行了探讨，结果如下：1.75MeV/u~(16)O~(8+)离子经过适当降能后注入小麦种子的不同部位和贯穿整个种子，对其M1代幼苗的可溶性蛋白质组分以及电脉中不同区段蛋白质组分相对含量加以分析，结果表明：1）同对照相比，随着辐照剂量的增加，所有辐照材料（包括贯穿和注入）第二区段（分子量较高区段）蛋白质组分的相对含量下降；而第五区段（分子量最小区段）蛋白质组分的相对含量升高。2）种子的贯穿处理，同时也引起第一区段（分子量最高区段）和第三区段蛋白质组分相对含量的下降以及第四区段的升高；其中第三、四区段的变化明显区别于注入效应。3）注入胚和胚乳的区别在于后者第一区段蛋白质组分相对含量的较大下降和第五区段的较大提高。4）小剂量辐照的材料，可溶性蛋白质组分的变化异常，可能与低剂量辐射兴奋效应有关。2.碳离子注入胚乳引起胚的后代发生变异，是典型的重离子诱变产生间接效应的结果。主要表现为：1）M1代的生物学性状、幼苗的抗氧化酶活性、MDA含量、蛋白质含量和染色体畸变率及微核率等发生了较大的变化。2）对其矮杆变异株和紫色茎杆突变体（M2）和RAPD和AFLP分子鉴定等研究，结果显示了矮杆变异体和紫色茎杆突变体的DNA序列发生了改变，而非仅仅产生生理损伤；同一种变异体或突变体，在M2代单株间也存在着明显的差异，表明它们可能还处于分离状态。于是，将M2代以上高代再种，以观察遗传能否稳定。3.重离子辐照普通小麦种子的M1代正常（它们可以完成生长发育的过程）植株同对照材料做正、反交，获得染色体组等来源不同的材料。接着对对照、M2代和正、反交材料DNA进行RAPD和AFLP多态性研究，并将实验结果作统计分析，结果表明：在细胞结构层次上，染色体组作为靶物质，产生的直接效应主要引起随机突变；而非染色体组的细胞组成的间接效应主要引起非随机突变。

强流高电荷态离子的产生和传输研究

本文对ECR离子源强流高电荷态离子的产生、金属离子的产生、强流多电荷态混合离子束的传输做了深入细致的研究。设计建造了一台全新的高电荷态ECR离子源-LECR3（兰州第三台高电荷态ECR离子源），该离子源的目标是产生强流高电荷态离子，设计上应用了多种提高高电荷态离子产额的关键技术：采用了高磁场模式；在保证弧腔内壁处径向磁场的前提下尽量增大弧腔的内径；使用铝制等离子弧腔；应用负偏压技术；新的微波馈入方式。经过调试和优化，其结果达到了国际同类离子源最好水平，其中O7+和Ar11+的束流强度为240eμA，O6+为780eμA，Xe26+为90eμA，Xe30＋也有6eμA。目前该离子源已经投入原子物理实验平台供束近两年。进行了金属离子产生的研究，并且成功地为加速器提供了5种金属离子。设计了一种结构紧凑的微小型金属加热炉，经过调试和优化，用炉子加热法在离子源上产生了多种金属的高电荷态离子，其中Ca11+可以达到140eμA，针对该种炉子的缺点又设训一了一种高温炉；用MIVOC（Metallic Ionfrom VOlatile Colnpounds）法调试了镍和铁的离子，其中Fe13+的束流强度为140eμA，为目前国际同类离子源最好水平。提出了一种全新的研究低能强流多电荷态混合离子束传输的方法，包括理论和实验两部分，理论上采用蒙特卡罗方法来模拟离子的传输轨迹，考虑电荷交换和空间电荷效应的影响，自行编写了MCIB计算程序，并进行了初步计算；实验上采用单丝和Wien-Filter探测技术来监测混合束的传输路径和某一截而上的各不同元素种类和不同电荷态离子的密度分布，做了初步实验，并且对计算结果和实验结果做了比较和分析，给出了该类束流的传输特性。

强流脉冲离子束辐照45钢表面热效应的模拟

以Fourier瞬态传热方程为基础,确定了强流脉冲离子束(HIPIB)热效应的基本传热方程,对靶材45钢进行不同能量参数的HIPIB辐照热效应的模拟计算.针对离子注入金属内部的情况,在模拟束流加载方式上分别采用体加载和面加载,比较了两种加载计算结果之间的差距.本算法的另一个改进就是在高能量辐照下,用单元死活法对蚀坑部分材料的消失进行模拟.结果表明,用单元死活法模拟单元的失效,更能符合HIPIB辐照金属表面热效应的蚀坑机制;单元死活法对靶材的升温过程没有明显影响,但对冷却阶段,可以显著提高模拟的精度.