医用重离子回旋加速器径向探针系统（英文）

武威和兰州重离子加速器使用回旋加速器作为其注入器。回旋加速器为该装置的同步加速器提供10μA的碳离子束流以满足其物理需求。而径向探针则是安装在回旋加速器内部实现束流流强和圈图测量的重要束诊元件。径向靶头上的束流信息经前端电子学拾取后会进一步进入数据采集系统,最终实现回旋加速器的束流流强和圈图测试。其中,径向探针的前端电子学采用皮安表,数据采集系统基于实时操作系统和FPGA技术。介绍了径向探针的机械结构设计,并分析了探头有无水冷结构的热结构;描述了控制系统软硬件架构,可以实现10 kHz的数据和位置信息的同步采集。最后,还介绍了探针机械和控制系统的实验室测试和验收标准以及在束测量结果。     

元素在探针表面上的原子化机理研究

探针原子人经法是一种新技术，本文系统地总结了用探针原子化法研究Ａｕ（１Ｂ），Ｓｒ（ⅡＡ），Ｃｄ（ⅡＢ），Ａｌ（ⅢＡ），Ｌａ，Ｓｍ，Ｆｕ（ⅢＢ），Ｇｅ，Ｓｎ，Ｐｂ（ⅣＡ），Ｓｂ，Ｂｉ（ⅤＡ），Ｖ（ⅤＢ），Ｃｒ，Ｍｏ（ⅥＢ），Ｍｎ（ⅦＢ），Ｆｅ，Ｃｏ，Ｎｉ，Ｐｔ（Ⅷ）等２０个元素的原子化机理了起源于卤化物分解的元素有Ａｕ与Ｐｔ，起源于氧化物分解的元素有Ｃｄ，Ａｌ，Ｌａ，Ｓｍ，Ｅｕ，Ｇｅ，Ｍｎ与Ｆｅ。     

HIRFL—CSR电子冷却系统

建议中的兰州重离子加速器冷却贮存环（ＨＩＲＦＬ－ＣＳＲ）拟采用电子冷却方法将重离子束冷却到３００ＭｅＶ／ｕ。最高电子能量为１６５ｋｅＶ，最大电子电流密度主０．２４４Ａ／ｃｍ＾２，叙述了ＣＳＲ电子冷却装置的初步方案。     

潘诺夫斯基教授荣获中国国家国际科技合作奖

 ２００１年４月５日中华人民共和国科技部举行隆重颁奖仪式,将国家科技合作奖奖牌正式授予潘诺夫斯基教授。众所周知,潘诺夫斯基（Ｗ．Ｋ．Ｈ．Ｐａｎｏｆｓｋｙ）教授系高能物理学家,无论作为一名科学家,还是任所长领导一职,在其职业生涯中,都充分显示出他不仅是一位著名的物理学家,而且还是一位杰出的加速器建造专家。在他担任所长期间,斯坦福直线加速器中心,（ＳＴＡＮＦＯＲＤＬＩＮＥＡＲＡＣＣＥＬＥＲＡＴＯＲＣＥＮＴＥＲ,简称ＳＬＡＣ）成功地建造了ＳＰＥＡＲ,ＰＥＰ和ＳＬＣ对撞机,并取得了许多有趣的重要物理成果,包括３个诺贝尔物理奖：发现质子并不是一个点粒子而有内部构造.     

准孤子在负平均色散补偿光纤链中稳定传输的区域

本文研究了准孤子在负平均色散补偿光纤链中稳定传输时ＤＣＦ和ＳＭＦ的配置关系,计算了准孤子稳定传输的区域,给出了直观的稳定传输区域图。数值模拟验证表明,稳区图的预言基本正确。     

紫外宽调谐激光晶体

Ｃｅ：ＬｉＣＡＦ和Ｃｅ：ＬｉＳＡＦ是目前最有效和连续调谐的紫外固体材料，文章介绍了ＣｅＬ：ＬｉＣＡＦ和Ｃｅ：ＬｉＳＡＦ晶体结构、生长、激光特性及其发展前景     

FISHBASE：一个加速器腔设计专用DBMS原型

开发设计了一种用于加速器设计的数据库管理系统原型,即ＦＩＳＨＢＡＳＥ。该系统采用一与目前较流行的通用数据库管理系统ＦＯＸＢＡＳＥ相类似的界面。对于腔内电磁场的计算,则是移植了ＳＵＰＥＲＦＩＳＨ的代码。     

扫描探针显微学在材料表面纳米级结构研究中的新进展

应用扫描探针显微技术（ＳＰＭ）「包括扫描隧道显微镜（ＳＴＭ）、原子力显微镜（ＡＦＭ）、磁力显微镜（ＭＦＭ）等」,比较系统地研究了一些无机、有机和生物材料的表面精细结构;在极高分辨率的水平上,解释了如Ｃ６０Ｌａｎｇｍｕｉｒ－Ｂｌｏｄｇｅｔｔ膜、有机磁性薄膜的样品制备、形成条件的关系;研究并揭示了碱金属与半志体表面吸附相互作用,红细胞表面结构等;拓宽了扫描探针显微技术的范围,在实验方法和研究成果上具有     

GPC－FTIR联用测定共聚物SBS的结构分布

凝胶渗透色谱仪（ＧＰＣ）与傅里叶变换红外光谱仪（ＦＴＩＲ）联用，以ＣＳ２为流动相，获得了共聚物ＳＢＳ的ＧＰＣ馏分的红外光谱图。根据图上各分离时间切片的红外光谱数据，计算出各相应时间切片的化学结构组成。结合经普适校正法获得的ＳＢＳ分子量分布的结果，采用自己编程的ＧＰＣ－ＦＴＩＲ－ＳＢＳ软件对ＳＢＳ的结构随分子量的变化进行了测定，得到了ＳＢＳ化学结构－分子量的分布图。     

2001年国际会议预告

ＪａｎｕａｒｙＪａｎ６—１１ＡＡＰＴａｎｄＡＡＳＪｏｉｎｔＷｉｎｔｅｒＭｔｇＳａｎＤｉｅｇｏ,ＣＡＣｏｎｔａｃｔ：ＡＡＰＴｏｒＡＡＳＦｅｂｒｕａｒｙＦｅｂ１２—１４ＰｈｏｔｏｎｉｃｓＷｅｓｔＳａｎＪｏｓｅ,ＣＡＣｏｎｔａｃｔ：ＳＰＩＥＦｅｂ１８—２３ＯｐｔＦｉｂｃｒＣｏｍｍｕｎｉｃａｔｉｏｎＣｏｎｆ（ＯＣＦ２００１）ＳａｎＦｒａｎｃｉｓｃｏ,ＣＡＣｏｎｔａｃｔ：ＯＳＡＭａｒｃｈＭａｒ１２—１６ＡＰＳＭａｒｃｈＭｔｇＳｅａｔｔｌｅ,ＷＡＣｏｎｔａｃｔ：ＡＰＳＡｐｒｉｌＡｐｒ１７—１９ＭＲＳＳｐｒｉ…     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Hybrid Wavelength and Code Division Multiple Access in Optical Networks

A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.     

Single-beam self-referenced phase-sensitive surface plasmon resonance sensor with high detection resolution

A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques.     

Influences of SiO2 protective layers and annealing on the laser-induced damage threshold of Ta2O5 films

Ta2O5 films are prepared on BK7 substrates with conventional electron beam evaporation deposition.The effects of SiO2 protective layers and annealing on the laser-induced damage threshold (LIDT) of the films are investigated.The results show that SiO2 protective layers exert little influence on the electric field intensity(EFI)distribution,microstructure and microdefect density but increase the absorption slightly.Annealing iS effective on decreasing the microdefect density and the absorption of the films.Both SiO2 protective layers and annealing are beneficial to the damage resistance of the films and the latter is more effective to improve the LIDT.Moreover,the maximal LIDT of Ta2O5 films is achieved by the combination of SiO2 protective layers and annealing.