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根据Paul离子阱结构及电场分布特点,列出阱内离子运动方程并求解,对其中离子运动、硅团簇离子碰撞解离反应进行了分析. 相似文献
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利用氦的渗透性质,向超高真空系统中充入高纯度氦缓冲气体,可以降低离子阱中囚禁离子的运动速度,减小二级多普勒频移,增加离子的存储时间,提高线型离子阱微波频标的稳定度.实验上得到了氦气渗透的实验参数、特性以及对系统真空度的影响、实现了用温度调节精确的控制充入氦气的分压强. 相似文献
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离子阱系统是实现量子计算和量子模拟的主要体系之一.世界范围内的各个离子阱研究小组共同推动着离子阱结构的丰富化发展,开发出一系列高性能的三维离子阱、二维离子芯片、以及具有集成器件的离子阱系统.离子阱的结构逐渐向小型化、高通光性和集成化方向发展,并表现出卓越的量子操控能力—对多离子的囚禁能力和精确控制能力越来越高.本综述将总结过去的十几年里离子阱在结构上的演化历程,以及离子阱在量子计算与量子模拟实验研究中的最新进展.通过分析具有代表性的离子阱结构,总结离子阱系统在加工工艺、鲁棒性和多功能性等方面取得的进步,并对基于离子阱系统的可扩展量子计算与模拟作出展望. 相似文献
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Paul离子阱由于没有外加磁场所引起的塞曼效应的影响,已成为离子存储及研究离子的重要装置.根据在实验中所采用的Paul离子阱结构及电场分布特点,列出阱内离子运动方程并进行求解,对其中各种运动进行分析,同时还分析了离子存储稳定性.最后对所作的研究进行总结,得到如下结论:阱中离子的运动为谐振运动、基频微运动和高阶微振动. 相似文献
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线型离子阱中的离子在射频场作用下做宏观的久期运动,久期运动频率与实验参数有关.但当离子阱中囚禁大量同种电荷的离子时,空间电荷效应会导致离子间存在相互排斥的库仑力,使离子的运动频率发生漂移.本文通过求解泊松方程计算了空间电荷产生的附加电场的解析表达式,在小振动近似下理论计算了该附加电场对久期运动频率的影响,模拟了不同离子云中心密度下久期频率的漂移,讨论了离子云的数目、温度与实验参数之间的关系.对用离子阱进行的频标实验、碰撞实验和其他方面的研究都具有重要的指导意义. 相似文献
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本文对最近研制的低温离子阱-离子速度成像谱仪进行升级,实现了探测离子光解反应的离子产物和中性产物速度影像的符合探测. 实验上利用自制的低温圆柱形离子阱对制备的离子样品进行富集和冷却. 从离子阱中引出的离子束准直后进入一组电势切换电极和离子速度聚焦成像系统开展激光光解实验. 利用一组新设计的离子引出、加速和聚焦电场,离子束可以被加速至4500 eV以上,使中性解离产物获得足够的平动能而被位置灵敏的影像探测器直接探测. 本文利用Ar2+离子的355 nm光解反应对升级后的装置进行测试. 结果表明,光解产生的中性Ar原子和Ar+离子产物的速度影像分辨率分别为Δv/v≈4.6%和1.5%. 相似文献
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D. T. C. Allcock T. P. Harty H. A. Janacek N. M. Linke C. J. Ballance A. M. Steane D. M. Lucas R. L. Jarecki Jr. S. D. Habermehl M. G. Blain D. Stick D. L. Moehring 《Applied physics. B, Lasers and optics》2012,107(4):913-919
We characterise the performance of a surface-electrode ion “chip” trap fabricated using established semiconductor integrated circuit and micro-electro-mechanical-system (MEMS) microfabrication processes, which are in principle scalable to much larger ion trap arrays, as proposed for implementing ion trap quantum information processing. We measure rf ion micromotion parallel and perpendicular to the plane of the trap electrodes, and find that on-package capacitors reduce this to ?10?nm in amplitude. We also measure ion trapping lifetime, charging effects due to laser light incident on the trap electrodes, and the heating rate for a single trapped ion. The performance of this trap is found to be comparable with others of the same size scale. 相似文献
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BaoQuan Ou Jie Zhang XinFang Zhang Yi Xie Ting Chen ChunWang Wu Wei Wu PingXing Chen 《中国科学:物理学 力学 天文学(英文版)》2016,59(12):123011
In this paper we report the optimal design and fabrication of a gold-on-silica linear segmented surface-electrode ion trap. By optimizing the thickness and width of the electrodes, we improved the trapping ability and trap scalability. By using some practical experimental operation methods, we successfully minimized the trap heating rate. Consequently, we could trap a string of up to 38 ions, and a zigzag structure with 24 ions, and transport two trapped ions to different zones. We also studied the influences of the ion chip surface on the ion lifetime. The excellent trapping ability and flexibility of operation of the planar ion trap shows that it has high feasibility for application in the development a practical quantum information processor or quantum simulator. 相似文献
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Cuneo M.E. Menge P.R. Hanson D.L. Fowler W.E. Bernard M.A. Ziska G.R. Filuk A.B. Pointon T.D. Vesey R.A. Welch D.R. Bailey J.E. Desjarlais M.P. Lockner T.R. Mehlhorn T.A. Slutz S.A. Stark M.A. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1997,25(2):229-251
Uncontrolled plasma formation on electrode surfaces limits performance in a wide variety of pulsed power devices such as electron and ion diodes, transmission lines, radio frequency (RF) cavities, and microwave devices. Surface and bulk contaminants on the electrodes in vacuum dominate the composition of these plasmas, formed through processes such as stimulated and thermal desorption followed by ionization. We are applying RF discharge cleaning, anode heating, cathode cooling, and substrate surface coatings to the control of the effects of these plasmas in the particular case of applied-B ion diodes on the SABRE (1 TW) and PBFA-X (30 TW) accelerators. Evidence shows that our LiF ion source provides a 200-700 A/cm2 lithium beam for 10-20 ns which is then replaced by a contaminant beam of protons and carbon. Other ion sources show similar behavior. Our electrode surface and substrate cleaning techniques reduce beam contamination, anode and cathode plasma formation, delay impedance collapse, and increase lithium energy, power, and production efficiency. Theoretical and simulation models of electron-stimulated and thermal-contaminant desorption leading to anode plasma formation show agreement with many features from experiment. Decrease of the diode electron loss by changing the shape and magnitude of the insulating magnetic field profiles increases the lithium output and changes the diode response to cleaning. We also show that the LiF films are permeable, allowing substrate contaminants to affect diode behavior. Substrate coatings of Ta and Au underneath the LiF film allow some measure of control of substrate contaminants, and provide direct evidence for thermal desorption. We have increased lithium current density by a factor of four and lithium energy by a factor of five through a combination of in situ surface and substrate cleaning, substrate coatings, and field profile modifications 相似文献
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We have built and characterized a novel linear ion trap. Its small horizontal electrode separation of 250?μm would previously have required microfabrication methods, while our trap was machined conventionally. The thin trap is designed to accommodate a transverse optical cavity of 0.5?mm length, a requirement for cavity-QED experiments with trapped ions in the strong coupling regime. The sandwich structure of the electrodes allows for a very accurate alignment. Employing the Doppler-recooling method, we found that intermittent laser-induced radiation pressure has a significant effect on the ion’s spectrum. This must be taken into account to correctly determine the heating rate of the trap. To this end, we have derived an analytic expression for the spectral line shape of the ion, which includes the effect of natural line broadening, heating as well as radiation pressure. We apply it to determine the accurate heating rate of the system. 相似文献
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We describe a new electrode design for a grooved surface-electrode ion trap,which is fabricated in printed-circuitboard technology with segmented electrodes.This design allows a laser beam to get through the central groove to avoid optical access blocking and laser scattering from the ion trap surface.The confining potentials are modeled both analytically and numerically.We optimize the radio frequency(rf) electrodes and dc electrodes to achieve the maximum trap depth for a given ion height above the trap electrodes.We also compare our design with the reality ion chip MI I for practical considerations.Comparison results show that our design is superior to MI I.This ion trap design may form the basis for large scale quantum computers or parallel quadrupole mass spectrometers. 相似文献
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Seidelin S Chiaverini J Reichle R Bollinger JJ Leibfried D Britton J Wesenberg JH Blakestad RB Epstein RJ Hume DB Itano WM Jost JD Langer C Ozeri R Shiga N Wineland DJ 《Physical review letters》2006,96(25):253003
Individual laser-cooled 24Mg+ ions are confined in a linear Paul trap with a novel geometry where gold electrodes are located in a single plane and the ions are trapped 40 microm above this plane. The relatively simple trap design and fabrication procedure are important for large-scale quantum information processing (QIP) using ions. Measured ion motional frequencies are compared to simulations. Measurements of ion recooling after cooling is temporarily suspended yield a heating rate of approximately 5 motional quanta per millisecond for a trap frequency of 2.83 MHz, sufficiently low to be useful for QIP. 相似文献
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Fluid simulation of the pulsed bias effect on inductively coupled nitrogen discharges for low-voltage plasma immersion ion implantation 下载免费PDF全文
Planar radio frequency inductively coupled plasmas(ICP) are employed for low-voltage ion implantation processes,with capacitive pulse biasing of the substrate for modulation of the ion energy. In this work, a two-dimensional(2D) selfconsistent fluid model has been employed to investigate the influence of the pulsed bias power on the nitrogen plasmas for various bias voltages and pulse frequencies. The results indicate that the plasma density as well as the inductive power density increase significantly when the bias voltage varies from 0 V to-4000 V, due to the heating of the capacitive field caused by the bias power. The N+fraction increases rapidly to a maximum at the beginning of the power-on time, and then it decreases and reaches the steady state at the end of the glow period. Moreover, it increases with the bias voltage during the power-on time, whereas the N_2~+ fraction exhibits a reverse behavior. When the pulse frequency increases to 25 kHz and40 kHz, the plasma steady state cannot be obtained, and a rapid decrease of the ion density at the substrate surface at the beginning of the glow period is observed. 相似文献
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Effect of annealing temperature on determining trap depths of quartz by various heating rates method
The aim of this study is to determine the trap parameters (trap depth E, frequency factor s) of quartz using various heating rates method and also to investigate the effect of annealing temperature on determining trap depths. The method is based on the positions of the thermoluminescence peaks, obtained from the change in temperature of the peak at maximum caused by changing the heating rate at which the sample is measured. In the present work, powder quartz samples were annealed first at different temperatures before irradiation. Then samples irradiated to different doses were measured with a TL reader at different heating rates and the glow curves were recorded. In order to calculate the trap depth E and the frequency factor s, the glow parameter Tm was determined experimentally from the glow curve by measuring the shift of the maximum peak temperature depending on heating rate β. The calculation of trap parameters was repeated for each annealing temperature. Then the effect of annealing temperature on trap depths calculated by the various heating rates method was evaluated. 相似文献
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在实验室天体物理研究中,电子束离子阱(EBIT)是极端紫外(EUV)和X射线波段能谱分析的重要实验平台,其中EBIT中心残余的中性气体对离子产生存在显著影响。研究了阱区中心残余中性气体对电荷态分布的影响,发现阱区中心残余中性气体和高电荷态离子之间的电荷/能量交换过程不仅影响离子的电荷分布, 而且对激发函数(离子分布比例随电子能量关系曲线)有着极大的影响。利用电离平衡分析方法成功诊断出阱区中心区域残留的中性气体分子数密度,以及内腔室的真空度。 相似文献