共查询到20条相似文献,搜索用时 171 毫秒
1.
杨晓天 《中国物理C(英文版)》2008,32(Z1)
介绍了国内外要求在极高真空条件下运行的部分粒子加速器概况;极高真空系统材料选择和处理工艺方面的进展;真空获得设备的选择和抽气方法的创新性进展;极高真空条件下的检漏方法研究及极高真空度的测量和校准现状. 相似文献
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HL—1M装置的真空进展 总被引:5,自引:2,他引:3
总结了1994 至1998 年度HL-1M 装置的真空进展,包括真空壁条件、真空运行参数、放电进展、影响壁条件的主要因素及其控制指标等 相似文献
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κ ������������ʷ��ˬ�����������º��� 《核聚变与等离子体物理》2018,38(3):350-356
总体描述了EAST机械臂真空舱系统设计,介绍了实现进展情况。EAST铰链式机械臂是用于在不破坏EAST内部真空环境下对第一壁内部进行近距离观测、快速维修的一种检修工具。考虑到对EAST铰链式机械臂的存储、支撑以及工作条件,需要设计和制造出一个密封的真空舱系统。该系统可以在真空条件下通过一个直径为250mm的连接端口连接到EAST主体机构上。系统设计主要分为真空存储舱CASK腔体、真空系统以及烘烤系统三个部分。 相似文献
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总体描述了EAST机械臂真空舱系统设计,介绍了实现进展情况。EAST铰链式机械臂是用于在不破坏EAST内部真空环境下对第一壁内部进行近距离观测、快速维修的一种检修工具。考虑到对EAST铰链式机械臂的存储、支撑以及工作条件,需要设计和制造出一个密封的真空舱系统。该系统可以在真空条件下通过一个直径为250mm的连接端口连接到EAST主体机构上。系统设计主要分为真空存储舱CASK腔体、真空系统以及烘烤系统三个部分。 相似文献
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本文基于IE514分离规结构, 建立了碳纳米管阴极电离规物理模型, 根据电离规标准方程, 利用离子光学模拟软件SIMION 8.0分别研究了电极电压对灵敏度和Igrid/Ie的影响. 结果表明, 随着阳极/门极电压比值增大(Vgrid/Vgate), Igrid/Ie也将增大, 然而, 当阳极电压增大时, 会导致灵敏度降低, 进而影响真空测量下限的延伸; 该模拟结果与相关文献报道的实验结果符合性很好. 因此, 选择合适的电极电压, 将有利于提高灵敏度, 增大阳极电流, 进一步延伸真空测量下限. 本文所采用的数值模拟方法可推广应用于各种新型碳纳米管阴极极高真空电离规的研发和理论分析中, 为解决极高真空测量难题提供了有效的研究途径.
关键词:
碳纳米管阴极电离规
电极电压
灵敏度
阳极电流 相似文献
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当代科学技术的发展,已经可以获得多方面的极端实验条件,例如,极强磁场和极弱磁场的获得与测量,极高压强和极高真空的获得与测量,极高温度和极低温度的获得与测量,等等.在这些极端条件下,常会出现一些新的现象,有的还可得到新的应用.在超低温度方面已经相继发展了1K到10-3K的mK区、10-3K到10-6K的μK区和10-6K到10-9K的nK区.在这些极低温度区域内,已经发现了碱金属原子和氢原子的玻色-爱因斯坦凝聚现象;氦-3和铜原子核的原子核磁矩有序的核磁有序(如核铁磁有序和核反铁磁有序)现象[1]… 相似文献
9.
利用电荷收集法,在正(135 V)、负(-117 V)偏置和低真空背景(0.5 Pa)三种不同收集条件下,测量了用于等离子体断路开关的电缆等离子体枪产生的低温等离子体的密度和漂移速率,测量值分别为8.3×1014,1.2×1015,4.8×1014 cm-3;2.5,2.0 cm·μs-1。测量结果表明:三种收集条件下测得的等离子体漂移速率相近;在相同测量点处,负偏置收集条件下测得的等离子体密度大于正偏置和低真空背景收集条件下的测量值,而低真空背景收集条件下的测量值最小。 相似文献
10.
研究了具有一定导电性能的碳纤维的直流场致发射电子束特性,实验分别在大气环境、低真空(10-1 Pa)及高真空(10-5 Pa)环境下进行。实验结果表明,碳纤维具有一定的场致发射能力,并且发射特性和发射环境的真空度密切相关。在大气环境下,发射电子束流与所施加的电压符合Fowler-Nordheim关系,当电压为7 kV,电流为61.4 μA时,根据Fowler-Nordheim定理推算出碳纤维场致发射场增强因子为3.75×105。在低真空条件下阳极只收集到微弱的电流;在高真空条件下,阴极发射明显,在较低电压下就能观测到阳极电流,放电前阳极最高电流是大气条件下的3~4倍,发射的束流大小和所施加在尖端的电压关系接近Child-Langmiur定律。 相似文献
11.
LIANGXian-Ting 《理论物理通讯》2004,42(4):535-538
We calculate the degree of entanglement for some bipartite entangled states of continuous variables.These states include common two-mode squeezed vacuum state, thermal vacuum state of a free single particle (where theh fictitious tilde system is regarded as another particle), and the squeezed vacuum state of two coupling harmonic oscillators.The degree of entanglement for these quantum systems are shown clearly by using the technique of integration within an ordered product of operators. 相似文献
12.
LIANG Xian-Ting 《理论物理通讯》2004,42(10)
We calculate the degree of entanglement for some bipartite entangled states of continuous variables.These states include common two-mode squeezed vacuum state, thermal vacuum state of a free single particle (where the fictitious tilde system is regarded as another particle), and the squeezed vacuum state of two coupling harmonic oscillators.The degree of entanglement for these quantum systems are shown clearly by using the technique of integration within an ordered product of operators. 相似文献
13.
Review: Aspects of Solution-generating Techniques for Space-times with Two Commuting Killing Vectors
Panayiotis Kordas 《General Relativity and Gravitation》1999,31(12):1941-1984
Certain aspects of solution-generatingtechniques for spacetimes with two commuting Killingvectors are reviewed. A brief historical introduction tostationary axisymmetric systems is given. The importance of the Homogeneous Hilbert problem associatedwith the equations, unifying the group-theoretic withthe soliton-theoretic approaches, is emphasized. Theformalism of generating functions is introduced, both for vacuum and electrovacuum.Sibgatullin's technique for electrovacuum solutions isrelated to the Hauser Ernst variables and a method byErnst is briefly discussed. The solitonic methods ofBelinsky-Zakharov and Alekseev are reviewed. Their relation isemphasized by an explicit proof, at the level ofgenerating techniques, that the BZ two soliton with twocomplex conjugate poles is isomorphic to the Alekseev one-soliton (restricted to vacuum) with trivialgauge. The Alekseev non-soliton technique is discussed.Some recent developments are brieflydiscussed. 相似文献
14.
The Navier-Stokes systems for compressible fluids with density-dependent viscosities are considered in the present paper.
These equations, in particular, include the ones which are rigorously derived recently as the Saint-Venant system for the
motion of shallow water, from the Navier-Stokes system for incompressible flows with a moving free surface [14]. These compressible
systems are degenerate when vacuum state appears. We study initial-boundary-value problems for such systems for both bounded
spatial domains or periodic domains. The dynamics of weak solutions and vacuum states are investigated rigorously.
First, it is proved that the entropy weak solutions for general large initial data satisfying finite initial entropy exist
globally in time. Next, for more regular initial data, there is a global entropy weak solution which is unique and regular
with well-defined velocity field for short time, and the interface of initial vacuum propagates along the particle path during
this time period. Then, it is shown that for any global entropy weak solution, any (possibly existing) vacuum state must vanish
within finite time. The velocity (even if regular enough and well-defined) blows up in finite time as the vacuum states vanish.
Furthermore, after the vanishing of vacuum states, the global entropy weak solution becomes a strong solution and tends to
the non-vacuum equilibrium state exponentially in time. 相似文献
15.
Degenerate parametric amplification accompanied by dissipation is analyzed within the canonical operator formalism for quantum dissipative systems named non-equilibrium thermo field dynamics. The vacuum of the system is subject to both dissipation and breaking of phase symmetry due to squeezing. The annihilation-creation operators for the vacuum are derived and the structure of the vacuum is examined. The effects of dissipation on squeezing and uncertainty relation are estimated. 相似文献
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介绍了EAST真空室内巡视系统(IVVS)系统对EAST真空室第一壁进行巡检操作的工作原理,并基于系统部分材料出气率测试对其真空性能进行了分析.获得了在有效抽速为1064L·s–1的条件下,IVVS系统试验样机所采用的真空容器的极限真空度为3.37×10–3Pa.为优化IVVS真空性能,结合材料放气率试验,将部分材料更换为放气率低的材料,对系统进行烘烤处理,并对其中的相关结构提出了优化方案.优化后系统的真空性能有明显提高,在同等抽速条件下的极限真空度在1×10–4Pa范围内,能够满足EAST接受的真空环境要求.此外,抽气机组增添低温泵可以更进一步提高系统的真空性能. 相似文献
18.
V. G. Usychenko 《Technical Physics》2005,50(5):551-559
The entropy of the steady state of an open electronic system is determined, and its relation to the entropy arriving at the
environment is established. The notion of system ordering is defined, and quantitative parameters characterizing ordering
are introduced. The information and conditional complexity of the system versus the state of thermodynamic chaos are determined.
These values are numerically estimated for vacuum, magnetron, and Gunn diodes. 相似文献
19.
介绍了EAST真空室内巡视系统(IVVS)系统对EAST真空室第一壁进行巡检操作的工作原理,并基于系统部分材料出气率测试对其真空性能进行了分析。获得了在有效抽速为1064L•s–1的条件下,IVVS系统试验样机所采用的真空容器的极限真空度为3.37×10–3Pa。为优化IVVS真空性能,结合材料放气率试验,将部分材料更换为放气率低的材料,对系统进行烘烤处理,并对其中的相关结构提出了优化方案。优化后系统的真空性能有明显提高,在同等抽速条件下的极限真空度在1×10–4Pa范围内,能够满足EAST接受的真空环境要求。此外,抽气机组增添低温泵可以更进一步提高系统的真空性能。 相似文献