Z“箍缩”的时间分辨测量技术研究

针对在阳加速器上进行的Z箍缩内爆实验所要求的超快分幅摄影技术研究,主要利用八个微通道板构成摄影系统的快门以达到时间分辨的要求,同时解决了在阳加速器上的精密同步问题以使系统可以稳定、可靠地一次拍摄到八幅图像,图像间隔最小为10 ns,曝光时间可达到3 ns.该技术以分幅原理获得大幅面的图像数据,具有图像特征清晰、空间信息详细的特点,为Z箍缩过程的研究提供了翔实的实验数据.     

Theory of a Two-Gas Gas-Puff Z Pinch

A simple snow-plow model for the two-gas gas-puff Z pinch is investigated. An expression for the plasma velocity in the central test-gas region is derived and the radius of maximum compression determined.     

Condition for Injection of Intense Relativistic Electron Beams into a Z Pinch

Intense relativistic electron beams have been injected into the plasma of a Z pinch at various times during the formation of the plasma column. If the diameter of the plasma column exceeded a certain value, these beams were found to propagate with a high transport efficiency when injected either into the collapsing current sheet of the Z pinch or into the expanding plasma column after its diameter had reached a minimum. However, when the diameter of the plasma column is smaller than this critical value, the relativistic electron beam does not propagate. Instead, it continues to diverge until it strikes the glass wall of the Z pinch tube.     

喷气式Z箍缩等离子体装置中离子束能谱的测量

利用新研制的紧凑型汤姆生离子能谱仪（ＴｈｏｍｓｏｎＩｏｎＥｎｅｒｇｙＡｎａｌｙｚｅｒ），对喷气式Ｚ－箍缩等离子体装置中离子能谱进行了测量，在ＣＲ－３９上得到了清晰的Ａｒ＋，Ａｒ２＋，Ａｒ３＋离子抛物线轨迹，通过分析计算结果表明：离子的最大能量在１ＭｅＶ左右，离子能谱分布曲线都随其能量增加而单调下降。     

Design of an Air-Core Reversed Field Pinch

The design of a small air-core reversed field pinch (RFP) is described. A numerical model was used to simulate the waveform of the plasma current and to improve the design of the air-core transformer.     

OHTE: A Helical Pinch with Pitch Reversal

The OHTE configuration is obtained by surrounding a reversed field pinch (RFP) with a stellarator-like helical winding whose pitch is chosen to enhance field line pitch reversal. The helical coil current needed to form a separatrix boundary is calculated analytically for a simple plasma model, which gives results in close agreement with a numerical two-dimensional (2-D) MHD equilibrium code. Basic properties of the field line transform, which is predominantly in the axial or toroidal direction, are investigated. The 2-D equilibrium code is used to investigate the effects of current profiles and high beta, and the OHTE is compared with the RFP. These calculations show that the helical winding can significantly enlarge the parameter space for interchangestable finite-? equilibria with pitch reversal while avoiding axial current reversal.     

Pinch Plasma Radiation Sources for the Extreme Ultraviolet

Extreme ultraviolet lithography (EUVL) is under discussion to be implemented in the production of chips as early as 2005 to 2007 for reducing structures in semiconductor devices to below 70 nm. The challenging task of developing optical components and radiation sources within this short period of time is pushing technology. As discharge produced and laser produced plasmas are the main candidates for EUV‐sources, plasma technology is forced to leap forward significantly. Progress in EUV‐sources is expected to open EUV‐technology for other applications in science and technology with increased need for spatial resolution, elemental contrast or sensitivity. Various technical concepts for realising high power sources for EUV lithography are under investigation world‐wide. Laser produced and discharge produced plasmas are the most promising schemes. Discharge produced pinch plasmas in general are of special interest, because their prospected costs (esp. cost of ownership) for the demanded throughput is expected to be much lower than with laser produced plasmas. However, the discharge plasmas are of high risk, because many crucial tasks have to be solved before reaching the required power levels. Beside the optimisation of the EUV‐generation ‐ which is the key to build the most reliable device with demanded EUV power ‐ the success will depend on the individual technical aspects of each source concept. Currently investigated pinch plasma concepts are evaluated based on their potential to be upgraded to fulfil the challenging demands of EUV‐lithography.     

Pinch effect and ampere tension to drive bering's pump

Contrary to Northrup's claim, the pinch effect, predicted by either the Biot-Savart law or the original Ampere law, accounts for less than half the necessary force to drive Hering's pump. The longitudinal Ampere tension, which is not predicted by the Biot-Savart law, is sufficient to account for the remaining force necessary.     

Pinch plasmas as intense EUV sources for laboratory applications

Compact pinch plasma devices are intense sources of pulsed EUV radiation with output energies of several joules per pulse in single lines. Their spectrum peaks in a wavelength range where conventional x-ray tubes provide poor intensity. With correct optimization, both continuous radiation or line radiation with / > 1000 can be produced for broadband and narrowband applications, respectively. Because of their low cost and their compact size, pinch plasmas seem well suited to supplement research activities based on synchrotron radiation.In this paper, pinch plasma sources developed for x-ray lithography and x-ray microscopy are described. Their emission characteristics are optimized with regard to specific requirements given by the particular application and are compared to laser produced plasmas. The lithography source is compatible with the electron storage ring printing process with respect to its spectrum and enables full-depth exposures in 1-m-thick 60 mJ cm^-2 sensitivity resist at resolution below 0.2 m within 10 minutes. The source for microscopy applications enables flash imaging of biological specimens with suboptical resolution (0.1–0.2 m) at nanosecond exposure times. In addition, the averaged plasma parameters meet the requirements for an EUV laser medium. The nitrogen 2–3 transition is especially promising for achieving amplified spontaneous emission of hydrogen-like or helium-like ions excited by three-body or charge exchange recombination.     

双层钨衬套Z箍缩内爆数值模拟

 介绍了在强脉冲电流的作用下双层钨衬套Z箍缩动力学过程的数值模拟,计算了一个双层钨衬套模型,分析了双层衬套的碰撞过程,指出了双层衬套下电磁内爆的现象和特点,给出了碰撞后电流在内外衬筒上的分布,并对箍缩功率和箍缩产生的能量进行了预估。     

Alfven Scaling of Magnetic Pulse Penetration in a Theta Pinch

Results of a code describing magnetic-field penetration into a plasma with theta-pinch geometry is presented. Classical coilisional effects can describe the Alfven velocity scaling but fail to account for observed penetration times and neutral density scaling.     

Z1/Z2 defects in 4H-SiC

First-principles calculations are carried out on models for the Z(1)/Z(2) defects in 4H-SiC which are found in as-grown and irradiated n-type material. We show that an interstitial-nitrogen-interstitial-carbon defect is exceptionally thermally stable, bistable, and has negative-U character with donor and acceptor levels close to those attributed to the defect.     

The structure of the Z 1 Z 2 → l + l − Z 1 Z 2 amplitude process outside the born approximation framework

Resummation of the perturbative series for the amplitude of lepton pair production in nucleus-nucleus collisions is performed based on the Watson theorem and the hypothesis of infrared stability. An explicit expression for this amplitude is obtained, which is valid to within terms of the ninth order in the fine structure constant.     

Z charmoniumlike mesons

A brief review of the experimental situation concerning the electrically charged charmoniumlike meson candidates, Z^-, is presented.