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Conceptual and technological evolutions of particle accelerators 总被引:1,自引:0,他引:1
We give here an ordered list of all types of particle accelerators and exhibit how each type evolves conceptually and/or technologically from the preceding. This is in contrast to the usual ``history of particle accelerators" in which unrelated accelerator types are listed in the chronological order. It is hoped that this discussion and understanding of the rationale and logic in the evolution of one accelerator type to the next will help to educe future inventions. 相似文献
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人类对于微观世界的探索是粒子加速器发展的驱动力.粒子加速器从20世纪30年代问世以来,不断向更高能量和更好性能挺进.随着研究的深入,粒子加速器一步步从低能发展到高能,从弱聚焦发展到强聚焦,从打静止靶发展到粒子束对撞.更高的能量和更高的亮度是用于高能物理研究的加速器发展的两大前沿.作为多学科研究的平台,同步辐射光源、自由电子激光和散裂中子源等基于加速器的大科学装置也在蓬勃发展.各种低能加速器广泛地应用于国民经济的各个领域.新方法、新技术、新原理层出不穷.文章将讨论国际粒子加速器的前沿. 相似文献
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Recent studies in complexity science have uncovered temporal regularities in the dynamics of impact along scientific and other creative careers, but they did not extend the obtained insights to firms. In this paper, we show that firms' technological impact patterns cannot be captured by the state-of-the-art dynamical models for the evolution of scientists' research impact, such as the Q model. Therefore, we propose a time-varying returns model which integrates the empirically-observed relation between patent order and technological impact into the Q model. The proposed model can reproduce the timing pattern of firms' highest-impact patents accurately. Our results shed light on modeling the differences behind the impact dynamics of researchers and firms. 相似文献
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文章介绍了与散裂中子源相关的高功率(几十千瓦到几兆瓦)质子加速器的发展状况,比较了不同类型的加速器组合的优缺点和它们的应用范围,并着重介绍该类型加速器所研究的主要加速器物理和加速器技术问题,其中很多都是当今国际粒子加速器领域的前沿问题.文中还简单地介绍了中国散裂中子源(CSNS)计划的加速器概念设计方案. 相似文献
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Ke-Xin Liu Yu-Gang Wang Tie-Shuan Fan Guo-Hui Zhang Jia-Er Chen 《Frontiers of Physics》2013,8(5):564-576
Electrostatic accelerator is a powerflfl tool in many research fields, such as nuclear physics, radiation biology, material science a.rchaeology and earth sciences. Two electrostatic accelerators, one is the single stage Vail de Gi'aaff with terminal voltage of 4.5 MV and another one is tile EN tamteIn with terminal voltage of 6 MV, were installed in 1980s and had been put into operation since the early 1990s at tile Institute of Heavy Ion Physics. Marly applications have been carried out since then. These two accelerators are described and summaries of the most important applications on neutron physics and technology, radiation biology and material science, as well as accelerator mass spectrometry (AMS) are presented. 相似文献
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单颗粒示踪(Single particle tracking,SPT)技术是应用显微镜系统对细胞内单个特定荧光或散射颗粒的定位和追踪。由于SPT能够实时监控活细胞内复杂、高度动态的组织结构的变化并提供结构—功能间的动力学关系,因此在细胞生物学上有重要的应用。本文总结了SPT的机理以及在细胞上的应用,首先介绍了SPT的动力学原理,包括单颗粒定位,轨道重建以及轨道分析,然后总结了SPT技术现阶段重点发展的光学材料及仪器,最后阐述了SPT在细胞膜、细胞内信号通路、分子转运机制、遗传信息表达以及病毒感染机制的应用。此外,本文还对SPT技术未来的发展进行了展望。 相似文献
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ZHANG Shan-Cai WANG Lin FENG Guang-Yao WU Cong-Feng LI Wei-Min XU Hong-Liang LIU Zu-Ping 《中国物理C(英文版)》2009,33(Z2)
The Hefei Advanced Light Source(HALS)is a super low emittance storage ring and has a very short beam life time.In order to run the ring stablely,top-up injection will be necessary.The injection system will greatly affect the quality of beam.This article first gives a physics design of the injecting system.Then the injecting system is tracked under different errors.The responses of storage beam and injecting beam are given in the article. 相似文献
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The Hefei Advanced Light Source(HALS) is a super low emittance storage ring and has a very short beam life time. In order to run the ring stablely, top-up injection will be necessary. The injection system will greatly affect the quality of beam. This article first gives a physics design of the injecting system. Then the injecting system is tracked under different errors. The responses of storage beam and injecting beam are given in the article. 相似文献
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机器学习技术在近十几年发展迅猛,并被广泛地用于解决复杂的科学和工程问题。最近十年间,基于机器学习的粒子加速器相关研究也开始呈现出井喷式发展趋势。国际上许多加速器实验室开始尝试用机器学习和大数据技术处理加速器中的海量复杂数据,以期解决加速器及其子系统中的诸多物理和技术问题。不过,迄今为止,机器学习在加速器中的应用仍处于初步探索阶段,不同机器学习算法在解决具体加速器问题的效果及其适用范围尚待摸索,机器学习在实际加速器中的应用仍非常有限。因此,有必要对加速器领域中的机器学习研究做一个整体回顾和总结。将回顾机器学习在大型粒子加速器(以储存环加速器和直线加速器为主)中的加速器技术、束流物理以及加速器整体性能优化等研究方向中已取得的研究成果,并探讨机器学习在加速器领域的未来发展方向和应用前景。
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压电加速度传感器是同振型矢量水听器的核心部件。为了满足低频高灵敏度矢量水听器的应用需求,提出并研究一种具有层合梁结构的低频高灵敏度加速度传感器。结合弹性力学和压电方程推导层合梁加速度传感器的加速度灵敏度解析解表达式,通过有限元仿真对层合梁加速度传感器尺寸进行优化,给出优化后的尺寸范围。从优化的尺寸范围中选取两种不同尺寸进行加速度传感器振动特性的仿真分析及实物制作(其中压电材料为PZT-5)与性能测试。仿真与测试结果均表明,相比已有的同尺寸金属梁加速度传感器,层合梁加速度传感器可以有效降低谐振频率并提升加速度灵敏度。当压电层厚度为0.5 mm时,加速度灵敏度最大提升3.9 dB,谐振频率下降23%。测试结果与理论分析相符。 相似文献
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为满足对中子散射谱仪关键部件的检测需求,提出一种基于反应堆中子源的中子标准测试束平台概念设计思路。该平台具有测试束流波长(0.1~0.3 nm)连续可调、n/可同步分析、样品台可多自由度移动以及便于后续拓展集成等优点。利用蒙特卡罗程序VITESS对平台整体结构,具体包括聚焦单色器、soller准直器等展开模拟优化分析。该装置利用可拆卸的准直器1实现高通量和较高分辨两种工作模式:工作于高通量模式时,样品台处中子(波长0.1 nm)束流强度最高可达6.15106 n/(cm2s),水平发散度1;工作于较高分辨模式时,分辨率可达0.2%。 相似文献
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V. I. Kaplin V. N. Karpinskii Yu. A. Polyakov V. I. Smirnov 《Physics of Particles and Nuclei Letters》2012,9(3):299-302
It is necessary for the power-consuming magnetic components of channels for beam transport in accelerators of charged particles be supplied with direct current. An individual power source is typically applied for each group of identical components. A variant of the simultaneous supply of several groups of magnets from a single medium-power source using auxiliary current shunts of different types is given by the example of a LEPTA positron storage ring. One version of using this technology with MW-power sources for a phasotron accelerator is developed. The efficiency of putting this technology into practice with the application of start-stop regimes for the phasotron is estimated. 相似文献
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Effects of adjacent bubble on spatiotemporal evolutions of mechanical stresses surrounding bubbles oscillating in tissues 下载免费PDF全文
Qing-Qin Zou 《中国物理 B》2023,32(1):14302-014302
The cavitation dynamics and mechanical stress in viscoelastic tissues, as the primary mechanisms of some ultrasound therapies, are extremely complex due to the interactions of cavitation bubble with adjacent bubbles and surrounding tissues. Therefore, the cavitation dynamics and resultant mechanical stress of two-interacting bubbles in the viscoelastic tissues are numerically investigated, especially focusing on the effects of the adjacent bubble. The results demonstrate that the mechanical stress is highly dependent on the bubble dynamics. The compressive stress and tensile stress are generated at the stage of bubble expansion and collapse stage, respectively. Furthermore, within the initial parameters examined in this paper, the effects of the adjacent bubble will distinctly suppress the radial expansion of the small bubble and consequently lead its associated stresses to decrease. Owing to the superimposition of two stress fields, the mechanical stresses surrounding the small bubble in the direction of the neighboring bubble are smaller than those in other directions. For two interacting cavitation bubbles, the suppression effects of the nearby bubble on both the cavitation dynamics and the stresses surrounding the small bubble increase as the ultrasound amplitude and the initial radius of the large bubble increase, whereas they decrease with the inter-bubble distance increasing. Moreover, increasing the tissue viscoelasticity will reduce the suppression effects of the nearby bubble, except in instances where the compressive stress and tensile stress first increase and then decrease with the tissue elasticity and viscosity increasing respectively. This study can provide a further understanding of the mechanisms of cavitation-associated mechanical damage to the adjacent tissues or cells. 相似文献