共查询到20条相似文献,搜索用时 93 毫秒
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两种气体离子源氮离子注入细菌的诱变效应比较 总被引:2,自引:0,他引:2
低能离子注入作为一种新的诱变育种手段已经得到广泛的应用.对考夫曼气体离子源和双潘宁气体离子源氮离子注入凝结芽孢杆菌的效果进行比较.经研究发现,在相同的引出电压下,考夫曼气体离子源注入的菌体到第三代的遗传稳定性要比双潘宁气体离子源注入的菌体高30%,但突变平均幅度要低2%,以此为依据可以根据不同诱变需要选择合适的离子源. 相似文献
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重离子注入与贯穿对作物种子萌发力的影响 总被引:3,自引:0,他引:3
离子注入植物种子是八十年代兴起的新技术。我国不少科学家首先在作物改良和生物研究方面取得了令人鼓舞的进展。重离子与χ、γ射线或中子相比,在生物诱变学方面有其明显的独特优势。例如重离子是高LET粒子,并具有Bragg峰。因此,它与生物体相互作用,同时发生... 相似文献
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中国离子注入生物效应研究(英文) 总被引:1,自引:0,他引:1
自从低能离子生物效应在中国发现以来,离子注入生物效应研究受到人们广泛的关注。低能离子束,作为新的诱变源已成功地应用于农作物和微生物改良;作为细胞加工的手段,已成为有效的转基因工具。文内简述了离子注入引起的生物效应的一些基本的现象;报道在群体、细胞和分子等不同层次上的分析结果;给出离子注入生物效应研究若干应用的实例;最后讨论这一研究领域要解决的一些问题和今后发展的方向。 相似文献
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强流离子源是EAST(Experimental Advanced Superconducting Tokamak)中性束注入器(Neutral Beam Injector,NBI)最关键的核心部件,其能达到的性能在很大程度上决定了EAST中性束注入器所能达到的指标。离子源在束引出时电极打火现象偶有发生,这对于离子源的正常运行有非常严重的影响,甚至危害离子源的寿命。本文结合离子源运行过程中的束引出实验波形和水流量热计(Water Flow Calorimetry,WFC)系统的测量数据得出等离子体发射面的束流光学系统一直处于非最佳聚焦状态是导致打火的原因,试通过优化高压投入时刻等离子体与高压的匹配,实现高压的稳定投入有效抑制打火现象的发生,并且给离子源加入硬件保护机制,为离子源安全稳定运行奠定基础。 相似文献
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Yahong XIE Chundong HU Jianglong WEI Yongjian XU Caichao JIANG Yuming GU Yuanzhe ZHAO Lizhen LIANG Yuanlai XIE 《等离子体科学和技术》2021,23(1):12001-5
In order to understand the physics and pre-study the engineering issues for radio frequency(RF)negative beam source, a prototype source with a single driver and three-electrode accelerator was developed. Recently, the beam source was tested on the RF source test facility with RF plasma generation, negative ion production and extraction. A magnetic filter system and a Cs injection system were employed to enhance the negative ion production. As a result, a long pulse of 105 s negative ion beam with current density of 153 A m-2 was repeatedly extracted successfully. The source pressure is 0.6 Pa and the ratio of co-extracted electron and negative ion current is around0.3. The details of design and experimental results of beam source were shown in this letter. 相似文献
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V. Toivanen O. Steczkiewicz O. Tarvainen T. Ropponen J. Ärje H. Koivisto 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(9):1508-1516
The results of a series of measurements studying the possibility to use neutral gas feeding into the beam line as a way to improve the quality of the heavy ion beams produced with an electron cyclotron resonance ion source (ECRIS) are presented. Significant reduction of the beam spot size and emittance can be achieved with this method. The observed effects are presumably due to increased space charge compensation degree of the ion beam in the beam line section between the ion source and the analyzing magnet. This is the region where the neutral gas was injected. It is shown that the effects are independent of the ion source tuning. Transmission measurements through the beam line and K-130 cyclotron have been carried out to study the effects of improved ion beam quality to the transmission efficiency. 相似文献
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In the experimental campaign of 2010 and 2011 on KSTAR, the NBI-1 system was equipped with one prototype ion source and operated successfully, providing a neutral beam power of 0.7-1.6 MW to the tokamak plasma. The new ion source planned for the 2012 KSTAR campaign had a much more advanced performance compared with the previous one. The target performance of the new ion source was to provide a neutral deuterium beam of 2 MW to the tokamak plasma. The ion source was newly designed, fabricated, and assembled in 2011. The new ion source was then conditioned up to 64 A/100 keV over a 2-hour beam extraction and performance tested at the NB test stand (NBTS) at the Korea Atomic Energy Research Institute (KAERI) in 2012. The measured optimum perveance at which the beam divergence is a minimum was about 2.5μP, and the minimum beam divergent angle was under 1.0° at 60 keV. These results indicate that the 2.0 MW neutral beam power at 100 keV required for the heating of plasma in KSTAR can be delivered by the installation of the new ion source in the KSTAR NBI-1 system. 相似文献
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离子源技术是等离子体研究中的一项重要内容,而低能大束流源则是离子源技术研究中的一个重要方向,因为这样的源在离子束刻蚀、离子束溅射镀膜以及荷能粒子与物质相互作用方面都有广泛的应用;本文采用空心阴极空心阳极结构,用热阴极电子发射弧放电驱动并用磁场约束产生等离子体,用曲面发射引出离子束,研制成了氩气放电溅射离子源;研究了灯丝加热电流、弧压对弧流的影响和弧流与工作气体压力对离子束引出的影响规律.离子源的引出电压在0-4.0 kV之间连续可调,最大引出束流为100 mA,束斑面积为φ6.0 cm,以Ti为溅射靶时的最大溅射沉积率为0.45 nm/s,离子源可连续工作160 h. 相似文献
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建立了用于蓝姆移动型极化离子源的双等源和低能引出聚焦系统,实验比较了等离子体出口孔径和聚焦电极之间的距离对引出束的影响,并调整了离子源的运行参数。离子束的质子比可达60%以上,满足了极化离子源的工作要求。约有4mA低能氢离子束(550eV)或氘离子束(1100eV)进入铯蒸汽电荷交换管道,在极化源上使用低能强流双等源后,可获得200nA左右的极化质子(或氘核)束。 相似文献
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束流剖面监测仪是监测带电粒子束在传输过程中状态变化的一种装置。该装置的叶片式探针(以下简称探针)安装在粒子加速器、同位素分离器和离子注入机等监测位置上并由它把截获的信号显示在示波器屏上便可观察到沿束横截面束流密度分布曲线(以下简称束形)。通过束形变化我们可定性地判断束流强度、束流品质和它在束管道中的相对位置等。因此,它在国外各种类型的粒子加速器上广为使用。 相似文献
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The neutral beam injector(NBI) system was designed and developed mainly for the plasma heating on the Experimental Advanced Superconducting Tokamak(EAST). The high power ion source is the key part of the NBI. A hot cathode ion source was used on the EAST-NBI. The ion source was conditioned on the ion source test bed with hydrogen gas and achieved the designed parameters. The deuterium gas was used when it moved to the EAST-NBI. The main performance of the ion source on EAST is presented in this paper. The highest beam power of 4.5 MW in NBI-1 and 2.75 MW in NBI-2 was achieved. The total neutral beam power is about 4.5 MW. The long pulse beam of 100 s is injected into the EAST plasma too. 相似文献
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