重离子辐射权重因数与辐射损伤模型研究进展

以第五届国际重离子在生物医学中应用会议和第十届国际辐射研究大会为背景，讨论了重离子生物学效应因数、辐射损伤生物物理模型和物理参数的表征等问题． Based on the fifth workshop on heavy charged particles in biology and medicine and the 10 th international congress of radiation research,the biological effects of heavy ions and biophysical models of heavy ions are discussed.     

利用高能离子模拟研究反应堆结构材料中的辐照效应

简要介绍了载能粒子辐射损伤对反应堆结构材料性能的影响，阐述了载能粒子束特别是高能离子束开展模拟研究的优势，并举例说明了国内利用高能重离子模拟研究反应堆结构材料辐射效应取得的进展。实验结果和理论分析表明，载能离子特别是高能离子辐照非常适合用于模拟研究反应堆结构材料中由粒子辐射引起的材料微观结构和宏观性能变化，是模拟研究反应堆结构材料辐射效应的非常有效的手段。 Radiation damage in structural materials of fission/fusion reactors is mainly attributed to the evolution of intensive atom displacement damage induced by energetic particles （ n, α and/or fission fragments） and highrate helium doping by direct α particle bombardments and/or （n, α） reactions. It can cause severe degradation of reactor structural materials such as surface blistering, bulk void swelling, deformation, fatigue, embrittlement, stress erosion corrosion and so on that will significantly affect the operation safety of reactors. However, up to now, behavior of structural materials at the end of their service can hardly be fully tested in a real reactor. In the present paper, damage process in reactor structural materials is briefly introduced, then the advantages of energetic ion implantation/irradiation especially high-energy heavy ion irradiation are discussed, and several typical examples on simulation of radiation effects in reactor candidate structural materials using high-energy heavy ion irradiations are introduced. Experimental results and theoretical analysis suggested that irradiation with energetic particles especially high-energy heavy ions is a very useful technique for simulating the evolution of microstructures and macro-properties of reactor structural materials.     

面向空间高能重离子与辐射屏蔽材料的反应截面地基研究

空间辐射尤其是高能重离子辐射可造成生物机体的严重损伤, 所以对高能重离子进行恰当的辐射屏蔽, 成为实现载人航天的关键性因素之一。 研究表明, 由于高能重离子与不同屏蔽材料发生相互作用, 所产生的核碎片等次级粒子, 直接影响空间辐射屏蔽材料的屏蔽性能研究和屏蔽结构设计。 介绍了太空辐射的分类与组成, 综述了国际地基辐射屏蔽材料与实验现状。 根据文献中的地基实验数据, 重点描述了被动式屏蔽方法: 以相近能量多种重离子, 不同能量的56Fe和28Si重离子分别与C, H, Al和Cu材料相互作用的总反应截面和碎片产生截面, 并结合510 MeV/u 56Fe与不同厚度CH2相互作用产生的碎片通量分布、 碎片平均LET分布和不同厚度CH2的单位入射离子剂量减少量等方面, 系统讨论分析了C, H, Al, Cu和CH2等常用空间辐射屏蔽材料的屏蔽性能。 Cosmic radiation, particularly the high energy heavy ion radiation, may cause serious injury on living organism. Therefore, it is one of critical restriction factor in Manned Spaceflight. Studies show that high energy heavy ions interacting with the shielding materials can produce numerous kinds of fragments and secondaries. These particles have a direct impact on evaluation of shielding properties of different shielding materials, the optimal shielding structure design and low dose evaluation after shielding materials. From perspectives of divisions of cosmic rays and passive shielding methods, this paper introduces the ground based research of shielding materials. The passive shielding method was discussed, based on the experimental data of the total cross sections and fragment（production） cross sections of the aspects of different heavy ions with approximately same energy and 56Fe, 28Si heavy ions with different energies on H, C, CH2, Al and Cu radiation shielding materials. In addition, the fragment fluency distribution, the average LET distribution and the dose reduction per particle of 510 MeV/u 56Fe in different depth of CH2 material were also discussed.     

C离子束放射治疗肿瘤的进展

重离子(C离子)用于肿瘤放射治疗具有物理学和生物学两方面的优势， 被誉为面向21世纪最佳放疗用射线。 综合论述了世界各国重离子束治癌的发展历史， 在日本国立放射医学综合研究所(NIRS)提供的临床试验数据基础上分析了C离子束治疗的适应症以及对正常组织的放射损伤。 此外， 通过分析潜在患者人数和治疗相关硬件与软件设备， 对C离子束治癌的运用前景做了初步评估。Heavy ions (carbon ions) were considered currently as the best radiation in radiotherapy for their two superiorities in the physical and biological properties. This paper firstly put the focus on the history of development of heavy ion radiotherapy in the world， then a comprehensive analysis of the indications and radiation damages of normal tissues in clinical trails of heavy ion therapy was made based on the published data by NIRS. Moreover, the prospect of using carbon ions in radiotherapy was estimated by analyzing the potential patients’ number, its related instruments and etc.     

3D组织培养模型及其在辐射诱导旁效应研究中的应用

综述了3D细胞培养技术（TDCC）的发展, 3种主要的体外组织构建方法; 辐射诱导2D细胞产生旁效应的现象与机理; 人工构建的3D组织辐射后诱导的旁效应及其细胞间信号传导机理。 重离子（C离子）辐照作为一种重要的放疗工具, 对其辐射处理3D组织后诱导产生的旁效应进行了展望。 由于3D组织更接近人体细胞生长的真实环境, 因而以3D组织作为模型研究辐射诱导的旁效应, 对于辐射旁效应的防护和治疗可能具有重要的指导意义。 Compared with the cultured monolayer (2D) cells, three dimensional (3D) tissue could be more similar to the environment in vivo including the physical support, chemical factors, cell cell and cell matrix interaction and so on. With the development of three dimensional cell culture techniques (TDCC), 3D tissue is widely used in the areas of bystander effect research. This review focuses on introducing the TDCC method and its application in bystander effect research. First, the development process of 3D tissue culture method was introduced. Secondly, the induction of radiation induced bystander effects both in 2D cell and 3D tissue and its mechanisms were reviewed. Finally, because heavy ion (carbon ion beam) has been developed as a useful tool to cure solid cancer ,and the 3D tissue model is an ideal material to study the damages on body after being irradiated and to understand the underlying mechanisms, future study about heavy ion radiation inducing bystander effect in 3D tissue was discussed.     

大蒜素在重离子放射治疗中的潜在用途

综述了大蒜素对正常细胞的保护机制和对肿瘤细胞的抑制机制, 并将其与辐射保护剂和辐射增敏剂的作用机制进行了比较, 提出大蒜素在放射治疗中对正常细胞具有辐射保护效应, 而对肿瘤细胞具有辐射增敏效应。 设想大蒜素的辐射保护和辐射增敏这种双重效应及其他优点在肿瘤放射治疗中能提高辐射生物学效应, 进一步改善治疗效果, 在临床应用中具有潜在的价值。 Garlic has beneficial effects to protect against many diseases. It can not only protect normal cells from lesion, but also prevent tumorigenesis, proliferation, adhesion, invasion and metastasis. In this paper, the mechanisms of these functions of garlic were summarized and compared with radioprotector and radiosensitizer. We presented that garlic has both radioprotective effect on normal cells and radiosensitive effect on tumor cells. By right of its superiority, garlic can improve biological effect in the therapy of heavy ion. Therefore, it has potential value in clinical practice. That is worth for us to explore whether garlic has radioprotective and radiosensitive effect or not.     

Cross Sections of Barium Isotopes in Interaction of 60 MeV／u ^18O with Natural Uranium

The reactions induced by heavy ions lower than 10 MeV/u have been studied widely. Their reaction mechanism has been also understood in more detail. The contribution to the reaction cross sections in the low energy reactions comes mainly from complex nuclei and deep inelastic process. Early studies mainly focused on the nuclear collisions of low and high energies. In the recent years, great attention has been paid on the intermediate energy heavy ion collisions. Among them measurements of the cross sections and recoiling properties for the target fragmentation products have been applied widely to study the mechanism of the nuclear reactions induced by the intermediate energy heavy ions. But there are a few papers on raodioehemieal studies in the intermediate energy region up to now.     

辐射基因治疗在肿瘤治疗中的研究现状

目前肿瘤基因治疗尚存在许多问题, 距临床应用还有相当的距离, 但是在传统的放疗、化疗和手术治疗的基础上, 辐射与基因治疗的有机结合在肿瘤治疗中却显示出可喜的前景。综述了近年来这一领域的研究进展, 探讨了这一疗法对肿瘤治疗的应用前景。Although tumor gene therapy has a distance to clinical use due to some problems, the combination of irradiation and gene therapy holds much promise in cancer therapy based on the traditional radiotherapy, chemotherapy and surgery. We have termed this therapeutic radiogenic therapy. This review focuses on the group of radiogenic therapy that are either: ⑴ improvement of gene transfer efficiency by irradiation; ⑵ radiotherapy combined with cytokines gene delivery or enhancement of the immunity of tumor cells by transgene; ⑶ directly stimulated by radiation to produce either directly or indirectly cytotoxic agents; ⑷ increasing of radiosensitivity in gene therapy; ⑸ radioprotective gene therapy enhances radiation tumor killing effect while protecting the normal tissue and organs with transgene using transfer vector.     

Cluster states prepared by using hot trapped ions

We propose a scheme for the preparation of one-dimensional and two-dimensional cluster states by using hot trapped ions. The scheme is based on the interaction between two ions and bichromatic radiation. The vibrational mode in our protocol is only virtually excited so that the system is insensitive to the thermal field. In addition, we only use two levels of ions as qubits and the successful probability may achieve 100%.     

Response of Alanine Dosemeter to Heavy Ions

The amino acid L-α-alanine has been investigated for use as a radiation detector in low and high LET radiation fields[1]. The radiatioa detector is cheap and easy to handle. The radiation inducing free radicals are stable at normal laboratory conditions for doses below 10^4 Gy over a long period of time, which makes the detector useful for intercomparison and documentation purposes. The dosimetric features of alanine-based electron spin resonance (ESR) detectors in high energy electron beams used in radiotherapy were considered[2]. The 5 mm long alanine detectors were found to be the most suitable for carrying out in vivo dosimetry on patients undergoing electron beam radiotherapy. However, data concerning dosimetry of the alanine dosemeter to heavy charged particles are lacking, especially in China.     

利用基于~1H NMR的代谢组学分析研究重离子辐射对大鼠额叶皮质区的影响

太空辐射尤其是重离子辐射可造成DNA的破坏、细胞死亡、以及一些癌症的发生, 是人类深空探索进程中急需克服的难题. 本文通过重离子加速器产生 ~(12)C~(6+)重离子束对大鼠头部进行一定剂量的辐射, 模拟空间重离子辐射对中枢神经系统(CNS)的生物学效应. 采用基于 ~1H NMR的代谢组学方法对辐射大鼠大脑额叶皮质区进行了测定分析, 结合数据的统计分析和检验, 发现了包括一些重要CNS神经递质在内的代谢物含量发生明显变化. 这些代谢物主要为: 牛磺酸、乳酸、谷氨酸、 4-氨基丁酸、以及磷酸胆碱等. 结合差异蛋白质组结果分析, 包括4-氨基丁酸、谷氨酸、乳酸、牛磺酸等在内的代谢物参与的主要生物途径, 如神经递质的合成途径, 以及神经递质受体介导的信号途径可能受重离子辐射的负面影响. 这些发现将为进一步阐明重离子辐射效应的分子机制提供有利信息, 从而为从生物学途径探寻有效重离子辐射防护措施提供依据.     

Monitoring by Raman spectroscopy of the damage induced in the wake of energetic ions

This article reports micro‐Raman experiments performed on cross sections of 6H‐SiC crystals irradiated with heavy ions of different energies. The results demonstrate that this technique is very powerful to quantify the damage created in the wake of energetic ions from the surface of samples down to the ion resting position. For slow ions (900‐keV I), ballistic collisions lead to the amorphization of the surface region of samples. For swift ions (36‐MeV W), the surface region remains crystalline and amorphization occurs around the end of the ion path. Moreover, synergistic effects between electronic and nuclear slowing down processes are put forward. The methodology used in this work may be adapted to other materials where radiation effects need to be investigated, provided that the damage created by irradiation is detectable by Raman spectroscopy. Copyright © 2014 John Wiley & Sons, Ltd.     

离子微束技术及其多学科应用

通过微米孔准直或电磁聚焦技术可将加速器产生的MeV离子束形成微米尺寸的离子束斑(微束), 从而用来研究固体和生物样品的微米空间分辨的材料信息和辐照响应。 结合MeV离子微束的发展历史综述了微束技术和跨学科应用, 包括利用微束开展具有空间分辨的离子束分析、 单粒子效应、 微纳加工和细胞辐射响应等研究。 介绍了中国科学院近代物理研究所的高能重离子微束辐照装置, 该装置成功地将总能量为1 GeV的C离子在大气中聚焦为1 μm×2 μm的微米束斑。 Beam of MeV ions from particle accelerators can be confined by collimators or focused by electrical/magnetic quadruples into micrometer size, and this microbeam can be used to obtain spatial information or radiation effect in solids and biological samples. This paper reviews the technical developments and the multi disciplinary applications of microbeam, including ion beam analysis, single event effect in semiconductor devices, proton beam writing and cellular response to targeted particle irradiations. Finally, the high energy heavy ion microbeam facility at the Institute of Modern Physics of Chinese Academy of Sciences is introduced, which has successfully focused 1 GeV Carbon ions into a beam spot of 1 μm×2 μm in air.     

利用HIRFL高能重离子束的核能材料辐照损伤研究

载能重离子与高能中子在材料中能够产生相似的级联碰撞损伤，加之重离子具有大的离位损伤截面和在材料样品中低的感生放射性，载能重离子束成为模拟先进核能装置内部结构材料辐照损伤的重要手段。HIRFL能区的重离子在结构材料中的射程一般远大于晶粒尺寸，因此能够产生材料体损伤，借助小样品技术可以获得材料力学性能变化（尤其辐照脆化）的有用信息，为探讨材料辐照损伤微结构和宏观力学性能变化的关联提供了重要条件。本文简要介绍了近年来我们基于HIRFL高能离子束开展的聚变堆候选材料辐照损伤的研究，包括低活化钢的辐照脆化行为、氧化物弥散强化（ODS）铁素体钢的结构优化对于抗辐照性能的影响、不同载能粒子辐照条件下铁素体/马氏体钢的辐照肿胀数据的关联，以及高能重离子辐照的钨材料中氢同位素的滞留行为。研究表明，结合特殊的测试技术及数据分析方法，高能重离子可作为核能结构材料辐照损伤研究及评估的有效手段。Because of the similarity in cascade damage structure in materials produced by energetic heavy ions and by fast neutrons, and the high displacement rate and low induced radioactivity of samples by heavy ions, heavy ion beam becomes an important tool to simulate radiation damage by energetic neutrons in materials in advanced nuclear energy systems. The ranges of heavy ions provided by HIRFL (Heavy Ion Research Facility in Lanzhou) are generally much larger than the mean dimensions of grains in alloys candidate to advanced nuclear reactors, and is capable of producing radiation damage in bulk scale. It therefore makes possible the evaluation of change of mechanical properties including the radiation induced embrittlement from the irradiated specimens by using miniaturized specimen techniques. In the present paper, we provide an introduction of our recent studies of radiation damage of materials candidate to future fusion reactors by utilizing heavy ion beams in HIRFL.The studies include issues as follows:ductility loss of RAFM steels causes by high-energy Ne ions, impact of oxide dispersoids on the radiation resistance of ODS ferritic steels, correlation of void swelling of ferritic/martensitic steels under different particle irradiation, and behavior of deuterium retention in tungsten under irradiation with high-energy heavy ions. The results show that high-energy heavy ions can be used as a tool to efficiently investigate or evaluate radiation damage in structure materials if combined with some special test techniques and data analysis.     

Damage production and annealing in ion-irradiated FCC metals

Abstract

Damage production, radiation annealing and stage I recovery in some FCC metals irradiated with ～ 1 MeV and ～ 100 MeV ions near 10 K are studied using electrical resistivity measurements. For ～ 1 MeV light and heavy ion irradiations, the fraction of stage I recovery and the damage efficiency decrease with the PKA median energy. For ～ 100 MeV heavy ion irradiations, an anomalous reduction of stage I recovery and a large cross-section for subthreshold recombination are found in Ni, and an enhancement of the damage efficiency is found in Cu; they are interpreted as due to the electron excitation by irradiating ions and the subsequent energy transfer from excited electrons to lattice atoms. Simultaneous differential equations describing the production and radiation annealing of two or more types of defects are solved, where the respective defect concentration is expressed as a function of fluence.     

ASPIRE: An automated sample positioning and irradiation system for radiation biology experiments at Inter University Accelerator Centre,New Delhi

An automated irradiation setup for biology samples has been built at Inter University Accelerator Centre (IUAC), New Delhi, India. It can automatically load and unload 20 biology samples in a run of experiment. It takes about 20 min [2% of the cell doubling time] to irradiate all the 20 samples. Cell doubling time is the time taken by the cells (kept in the medium) to grow double in numbers. The cells in the samples keep growing during entire of the experiment. The fluence irradiated to the samples is measured with two silicon surface barrier detectors. Tests show that the uniformity of fluence and dose of heavy ions reaches to 2% at the sample area in diameter of 40 mm. The accuracy of mean fluence at the center of the target area is within 1%. The irradiation setup can be used to the studies of radiation therapy, radiation dosimetry and molecular biology at the heavy ion accelerator.     

Measurement of the decay and time-resolved spectra of the emission from σ-excitons in KBr in the nanosecond range,produced by heavy-ion irradiation

While energetic heavy ions are currently in increasing use in solid state physics, radiation chemistry and biology, there is still little experimental information regarding the primary physicochemical processes. These high LET (linear energy transfer) ion particles injected into condensed matter produce short life-intermediates such as excited states, ions, and radicals, at high density along the track. The density effect of these intermediates may cause damage-formation and chemical reaction to yield different results compared with low LET radiation (γ, X-ray) or photo-irradiation. Electronically excited states, among the above intermediates, are thought to be especially important precursors. Measurements of the decay and time-resolved spectra of the emission are expected to give useful information regarding the radiation action of heavy ions. The measurements were done using a KBr single crystal at 4.2 K. We reported previously [1] that heavy ion irradiated KBr results in an extraordinarily large ratio of σ-emission to π-emission 2 intensity (～ 5 times larger than in the X- or electron-irradiation). This large ratio is, as was ascertained previously, not due to apparent processes such as temperature increase of a track but to intrinsic processes which will be discussed here.     

FPGA配置片反熔丝PROMs加速器地面单粒子效应特性研究

针对0.13 μm CMOS（Complementary Metal-Oxide-Semiconductor）体硅外延工艺下FPGA（Field Programmable Gate Arrays）配置片反熔丝PROM（Programmable-Read-Only-Memory）进行了单粒子效应（Single Event Effects SEEs）的加速器地面模拟试验研究。以PROM的存储容量、数据类型和工艺差异性为研究变量,考核与验证其在不同种类和能量粒子入射的系列性加速器地面SEEs模拟试验。研究结果表明,相对于8 Mbits PROM而言,空片16 Mbits PROM抗辐射性能最优,且从翻转饱和截面上说,16 Mbits的PROM具备更高的可靠性,优于国外同系列的芯片类型,试验用PROM芯片的单粒子锁定阈值>99.0 MeV·cm2/mg。另一方面,研究0.13 μm CMOS普通与深阱工艺技术下PROM芯片单粒子翻转效应异同性的实验数据表明,在高LET（Linear Energy Transfer）处的两者抗辐射性能并无明显变化,但是低LET处（LET翻转阈值）的加固效果较为明显,即抗辐射技术能力主要体现在LET翻转阈值的提升而非翻转截面的减小。Single event effects (SEEs) have been characterized and investigated on one-time configured devices for field-programmable-gate-arrays (FPGA) of programmable-read-only-memory (PROM) in 0.13 μm Complementary Metal-Oxide-Semiconductor (CMOS) technology.The variables of their memory size,written data and technology have been taken into consideration as the key parameters affecting the SEEs sensitivity when testing and verifying the reliability/radiation tolerance on self-made PROMs by heavy ions.The results show that,16 Mbits PROM within blanked data has been studied that it has better performance to radiation tolerance as compared with the 8 Mbits PROMs.Additionally,16 Mbits PROMs have the higher reliability,if based on the viewpoint of the saturated single event upset cross-section.To the single event latchup,16 Mbits PROMs were exposed to a total fluence of 107 ions/cm2 at the linear energy transfer (LET) of 99.0 MeV·cm2/mg and no obvious fluctuation of current has been observed.Additionally,as comparing the zone of high LET value,0.13 μm CMOS transistors with deep-well technology present a better radiation hardened approach than normal technology,especially in improving the threshold of LET at the zone of low LET value.