Dynamics of Self-Organized and Self-Assembled Structures,by Rashmi C. Desai and Raymond Kapral

The arrival of the first hard X-ray free electron laser facilities promises new advances in structural dynamics and nanoscale imaging that will have impact across the sciences. This introductory review is intended to cover the basic physics behind this potential and illustrate the current state-of-the-art by discussing a number of recent findings from the LCLS facility at the Stanford Linear Accelerator Centre (SLAC). We concentrate on the new science using these light sources rather than the new light source technology itself, although a brief introduction to the operation of LCLS is given. Emphasis is placed upon the new regime of high intensity X-ray matter interaction physics with ultrashort X-ray pulses. We discuss how the unique combination of X-ray parameters will open new opportunities for time resolved structural studies and how the high brightness enables a new class of coherent diffraction X-ray imaging. The potential importance of this new imaging method in the study of nanostructures and biological systems at the sub-cellular and molecular level will be outlined.     

NSLS‐II: A proposed new synchrotron at Brookhaven National Laboratory

A workshop on high-resolution X-ray emission spectroscopy was held in conjunction with the joint NSLS/CFN 2006 Users' Meeting. With the availability of high-brightness X-ray sources, and the development of improved optics and detectors for high-resolution (millivolt to volt) X-ray detection, X-ray emission spectroscopy (XES) has become one of the more rapidly growing areas of condensed matter synchrotron science. Most of the applications to date have focused on using XES for problems in condensed matter physics. The goal of this workshop was to illustrate the potential of XES for addressing important questions in chemistry and biology.     

强场X射线激光物理

相干X光,特别是X射线自由电子激光技术的发展提供了一种新的产生超强光场的途径.由于其较高的光子能量、高峰值功率密度与超短的脉冲长度,有望将强场激光物理从可见光波段推进到X光波段.目前,基于X射线的非线性原子分子物理已取得了初步进展,随着X射线光强的提升,相互作用将进入相对论物理、强场量子电动力学(quantum electrodynamics,QED)物理等领域,为激光驱动加速与辐射、QED真空、暗物质的产生与探测等带来新的科学发现机会.本文对强场X射线激光在固体中的尾场加速、真空极化、轴子的产生与探测等方面进行介绍,旨在阐明X射线波段强场物理在若干基础前沿与关键应用方面的独特优势,并对未来的发展方向进行展望.     

超快X射线自由电子激光研究进展北大核心CSCD

现代光源的发展不断推动着人们从更深层次上理解物质的基本结构和动力学行为。X射线自由电子激光作为最先进的光源,其超高的峰值功率、超短的脉冲长度和优良的相干性,为人们以原子级时空分辨率探测和操控物质中的超快过程提供了可能。目前全世界已有多个X射线自由电子激光装置建成并投入使用,在原子分子物理、化学、生命科学、材料科学等各学科应用中都显示出了重要价值。同时大量的研究工作也集中于继续提高X射线自由电子激光的性能,包括把脉冲持续时间从fs量级进一步缩短至as量级,这将为超快科学的发展带来新突破。以超快脉冲产生为主线,综述了近年来超快X射线自由电子激光产生方案的研究进展,从产生原理、方案特性、最新成果等方面介绍了各类产生方案,总结对比了各方案的优缺点,最后对超快X射线自由电子激光的未来发展方向进行了展望。     

High-resolution LMN and LMM Auger spectra of Pd,Ag, In,Sn and Sb

Considerable interest in high-resolution Auger spectroscopy of the 4d metals has arisen because of the possibility of treating Auger spectroscopy as an excited state probe in order to extract new information regarding electronic structure. Auger transitions involving only core levels are interesting because current theories of line shapes and energies usually assume that the final core holes are either atomic or quasi-atomic. Comparison of the results of atomic calculations with experimental Auger spectra comprises a crucial test of the atomic theories.We present the results of high-resolution measurements of several high energy LMN and LMM Auger spectra of Pd, Ag, In, Sn and Sb excited with Ti Kα radiation. Assignments of the peaks are based upon energy and intensity considerations. We compare the experimental spectra with the results of atomic transition probability calculations, which indicates the reliability of such calculations as we proceed from open to closed 4d shell metals.     

Count-rate,linearity, and performance of new backgammon detector technology

The meander wire backgammon technology has high levels of flux and spatial linearity across a wide range of energies. One of the attractive features of these technologies is the stability of response and robustness under long X-ray exposure, compactness, and portability. A key problem historically has been the limited range of count-rate for processing to the optimum resolution. We report dramatic advances in this and other areas appropriate for high-accuracy experiments including tests of quantum electrodynamics, fundamental relativistic atomic physics, X-ray calibration, and crystallography. We illustrate this technology applied to the Kα_1,2 spectra of titanium, chromium, and copper. The quality of the spectra permits deeper insight into atomic and solid state science and permits accurate measurement of energy and relativistic atomic physics processes, below 1-μm accuracy or down to 1 ppm in energy.     

Studies of high-repetition-rate laser plasma EUV sources from droplet targets

The water droplet laser plasma source has been shown to have many attractive features as a continuous, almost debris-free source for extreme ultraviolet (EUV) and X-ray applications. Through a dual experimental and theoretical study, we analyze the interaction physics between the laser light and the target. The hydrodynamic laser plasma simulation code, Medusa103 is used to model the electron density distribution for comparison to electron density distributions obtained through Abel inversion of plasma interferograms. In addition, flat field EUV spectra are compared to synthetic spectra calculated with the atomic physics code RATION. Received: 31 October 2002 / Accepted: 8 February 2003 / Published online: 28 May 2003 RID="*" ID="*"Present address: Naval Reseach Laboratory, Washington D.C. RID="**" ID="**"Present address: Xtreme Technologies, G?ttingen, Germany. RID="***" ID="***"Corresponding author. Fax: +1-407/823-3570, E-mail: mrichard@mail.ucf.edu     

Review and perspectives on energy dispersive high resolution PIXE and RYIED

Until 2008, high-resolution particle-induced x-ray emission (HR-PIXE) work used mostly wavelength dispersive spectrometers and aimed at fundamental problems and application demonstrations. The method was hardly used for applications in general, mostly due to the small energy window and solid angle of most equipment. In the last 14 years, a few facts pushed HR-PIXE out and beyond this framework. Here, we focus on the developments following the observation of x-ray relative yield ion energy dependence (RYIED) effects on transitions to the same sub-shell, in PIXE experiments, in 2004, and the installation, in 2008, of the first energy dispersive HR-PIXE (EDS HR-PIXE) system. Both facts are among those that were concurrent to the emergence of new problems and perspectives in PIXE and in fundamental atomic physics in the recent past. This review covers these 14 years of results on these issues and the answers they recently led to. Evidence for new problems and perspectives, including the potential access to chemical bonding and/or solid state information, based on EDS HR-PIXE work, are discussed. Furthermore, the grounds for the possibility of developments leading to a new field of atomic solid state physics are presented.     

极性分子的激光冷却及囚禁技术

分子由于其不同于原子的特殊性质,在原子、分子和光物理研究中有其独特的地位.冷分子研究已经开展了二三十年,取得了很多重大的进展.但是以斯塔克减速器为代表的传统冷却方案遇到瓶颈,很难进一步提高分子的相空间密度.将原子中成熟的激光冷却技术拓展到极性分子中是本领域近年来的重大突破,使得冷却和囚禁分子的范围得以大大扩展,分子的相空间密度也得以提高.本文对国内外激光冷却极性分子的最新成果进行综述,并以BaF分子为例介绍激光冷却极性分子的相关理论和技术,包括分子能级结构分析及精密光谱测量,采用缓冲气体冷却进行态制备和预冷却,以及通过冷分子束研究激光与BaF分子间的相互作用.这些为后续开展激光冷却与囚禁实验研究奠定了基础,也为开展其他新的分子冷却实验提供了参考.     

Physics of atomic collisions in retrospect

The classic work by Mott and Massey, in which the scope of the physics of atomic collisions was defined, was published about 65 years ago. Since then, this field has undergone considerable development. In fact, all the theoretical methods named by Mott and Massey have been implemented to some extent. As for experiment, the measurements performed, which are differential with respect to several parameters, have provided for reliable testing of the mechanisms proposed. The physics of atomic collisions has been developed to the point that we can look back on the road taken and discover many achievements which have promoted its development. Progress in science is usually associated with highly concentrated efforts on the part of a critical number of investigators to solve a specific problem, which is widely regarded as being of great importance. Such a “breakthrough” is usually followed by rapid development of the field. In this respect, the physics of atomic collisions is no exception. It has known periods of highly concentrated efforts aimed at solving specific problems and breakthroughs followed by rapid development and subsequent periods of stagnation. The cycles have repeated: a new area for concentrated efforts is discovered, a breakthrough occurs, and a new concept is established. Some of these cycles are analyzed from the standpoint of their significance to atomic physics as a whole. Zh. Tekh. Fiz. 69, 22–26 (September 1999)     

Ultrafast X-ray sources and applications

The recent development of ultrafast X-ray sources makes conceivable the analysis of subpicosecond transient structures. This paper describes these new techniques and reports the first experiments dedicated to the analysis of atomic motions on this time-scale.     

Observation of Fano resonance and classical analog of electromagnetically induced transparency in toroidal metamaterials

Toroidal multipoles have recently been explored in various scientific communities, ranging from atomic and molecular physics, electrodynamics, and solid‐state physics to biology. Here we experimentally and numerically demonstrate a three‐dimensionsal toroidal metamaterial where two different toroidal dipoles along orthogonal directions have been observed. The chosen toroidal metamaterial also simultaneously supports Fano resonance and the classical analog of electromagnetically induced transparency (EIT) phenomena in the transmission spectra that originate from the electric–toroidal dipole and electric–magnetic dipole destructive interference. The intriguing properties of the toroidal resonances may open up avenues for applications in toroidal moments generator, sensing and slow‐light devices.     

Scattering factor calculations and dispersion corrections for heavy atoms

Reliable knowledge of the complex X-ray form factor (Re(f) and Im(f)) is required for crystallography, deformation density bonding studies and refractive index studies. Dispersion corrections are important in DAFS, MAD analyses and XAFS studies. Discrepancies between currently used theoretical approaches of 200% exist for numerous elements from 1 to 3 keV X-ray energies, and at higher energies these discrepancies can persist at the 10% level or more. This has suggested that new formulations and new experimental approaches are necessary. Recent tabulations improve upon the theoretical uncertainty in some of these regions by a factor of 10 and reduce the error of this approach to below one standard deviation. Recent experimental developments have begun to probe alternate theory, providing a tool to investigate the significance of relativistic corrections and convergence criteria across a range of atomic number. In part, this has revealed that more theoretical work will be required in future years. Recent advances permit new probes and insights into atomic and solid state physics, as well as to many X-ray optical applications. This paper discusses significant improvements upon the theoretical uncertainty in near-edge regions, reducing the error of this approach to less than one standard deviation.     

等离子增强原子层沉积低温生长AlN薄膜

采用等离子增强原子层沉积技术在单晶硅基体上成功制备了AlN晶态薄膜, 利用椭圆偏振仪、原子力显微镜、小角掠射X射线衍射仪、高分辨透射电子显微镜、 X射线光电子能谱仪对样品的生长速率、表面形貌、晶体结构、薄膜成分进行了表征和分析, 结果表明, 采用等离子增强原子层沉积制备AlN晶态薄膜的最低温度为200 ℃, 薄膜表面平整光滑, 具有六方纤锌矿结构与(100)择优取向, Al_2p与N_1S的特征峰分别为74.1 eV与397.0 eV, 薄膜中Al元素与N元素以Al-N键相结合, 且成分均匀性良好. 关键词： 氮化铝 等离子增强原子层沉积 低温生长 晶态薄膜     

中国工程物理研究院的核物理、核技术及相关学科的研究

本文概要地介绍中国工程物理研究院的核物理、核技术及相关学科的研究与发展．内容包括九个方面;脉冲核反应体系的诊断学;中子学（微观与积分中子核数据、粒子输运）;高高化态原子物理学;激光惯性约束核聚变与高温高密度等离子体物理;Ｘ射线激光;加速器物理与技术（含自由电子激光与微波研究）:核电子学;核军备控制物理学及核技术应用等． This paper briefly introduces the research and development of nuclear physics,nuclear technology and related disciplines at CAEP.It contains nine brenches: diagnostics ofpulsed nuclear reaction assembly,neutronics multi-charged atomic physics, laser fusion andplasma physics, X-ray laser,accelerator physics and technology, nuclear electronics, nuclear arms control physics and applications of nuclear technology.     

Applications of X-ray absorption spectroscopy in materials science: Status and new trends

X-ray absorption spectroscopy (XAS) is a local probe of the geometric and electronic structure of individual atomic species in condensed matter. With the availability of intense, polarized and highly collimated X-rays from storage rings the technique has found a widespread application in physics, chemistry, biology and geology. Multiple scattering of the photoelectron in the edge region and in shadowing configurations makes it possible to deduce higher correlations in the atomic arrangement besides the pair correlation obtained from standard EXAFS. This gives radial and angular information on the geometric structure. A promising new application is XAS under total external reflection with detection of the absorption by fluorescence. This allows in-situ investigations of solid-solid, solid-liquid and solid-gas interfaces. New dedicated storage rings with high brilliance will have a major impact on XAS in dispersive mode and for very dilute systems.     

VUVX2010: 37th International Conference on Vacuum Ultraviolet and X-ray Physics

UVX2010, the 37^th International Conference on Vacuum Ultraviolet and X-ray Physics, took place from July 11-16, 2010, on the campus of the University of British Columbia (UBC). This meeting was the first of the merged Vacuum Ultraviolet Radiation Physics and X-ray and Inner Shell Processes conference series. The immediate preceding conferences were VUV15 (Berlin, 2007), and X-08 (Paris, 2008). VUVX2010 brought together scientists from countries all over the world working with synchrotron-, laser-, and plasma-based sources of electromagnetic radiation in the vacuum ultraviolet (VUV), soft X-ray, and hard X-ray regions, and developing novel applications of these sources in a variety of fields. Topics presented ranged from basic physics to materials science and technology, from molecular reactions to the characterization of catalysts under working conditions, from biology to medical diagnostics, from metrology to the development of advanced synchrotron and optical instrumentation. There were over 500 oral and poster presentations, with 480 attendees from 29 different countries. This conference took place on the fiftieth anniversary of the invention of the laser and in the year following the first operation of the Linear Coherent Light Source (LCLS), the world's first accelerator-based X-ray laser. It brought together the global community of VUV and X-ray scientists who use synchrotron-, laser-, and plasma-based sources of vacuum ultraviolet, soft X-ray, and hard X-ray light to explore new phenomena and to develop a better understanding of the physics of the interaction of light and matter.     

Method for high-resolution frequency measurements in the extreme ultraviolet regime: random-sampling Ramsey spectroscopy

Ramsey-like schemes have been recently introduced in combination with high-order laser harmonic sources for high-resolution spectroscopic studies in the extreme ultraviolet (XUV). Here we demonstrate a novel method, combining measurements only in a limited subset of randomly chosen time-sampling intervals, which lead us to perform the first high-resolution XUV spectroscopy of atomic argon with a simple split-pulse setup. Providing an experimentally simple and convenient solution to the problem of performing high-resolution absolute frequency measurements in the XUV, our approach will help paving new roads into this challenging spectral territory.     

Electro-weak interaction in muonic atoms

The parity non-conserving effective neutral current interaction between charged leptons and nucleons is studied in its implications for atomic physics. Present results on heavy electronic atoms are discussed within the standard electroweak theory and beyond. The new features provided by muonic atoms open the way to the nuclear-spin-dependent parity non-conserving effects. Different observables proposed to study these effects in muonic atoms are reviewed.     

高电荷态离子束的应用(摘要)

The ECR ion sources have mainly been used until now for injection of cyclotrons and a large number of these sources are presently in operation through the world.Most cyclotrons are used today for nuclear physics researches but an increasing number of these accelerators are now devoted to medical applications.The ECR ion sources have also been extensively used for producing low energy beams for academic researches in atomic and surface physics.These studies led to very encouraging results opening the way to industrial applications. In this talk some of the most promising applications of HCI beams will be reviewed.The development of these applications will require some important improvements of the ECR sources which will be discussed.A special emphasis will be given to the respective roles of ECR and EBIS ion sources in these industrial applications, and some economic and market considerations discussed.