bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent performance of the Photon Factory gratingcrystal monochromator station BL-1A in the soft X-ray region
Authors: Maeyama Satoshi , Sugiyama Munehiro
Published: July 2004

This paper describes the recent performance of the Photon Factory beamline 1A with InSb(111) crystals used as the diffracting elements of the grating/crystal monochromator for monochromatizing soft X-rays. Pt-coated collimating and focusing mirrors located upstream and downstream of the monochromator have recently been replaced with Ni-coated mirrors in order to remove absorption structures at the Pt M-edges from output spectra in the soft X-ray region. Output spectra without the absorption structures and with higher intensity in the range 2000–3400 eV were obtained by using the Ni-coated collimating and focusing mirrors.
Design and fabrication of highly heat-resistant Mo/Si multilayer soft X-ray mirrors with interleaved barrier layers
Authors: Takenaka Hisataka , Ito Hisashi , Haga Tsuneyuki , Kawamura Tomoaki
Published: July 2004

Introducing interleaved carbon barrier layers improves the heat-resistance of Mo/Si multilayers. The soft X-ray reflectivities of the multilayers were calculated, and the effects of heating on both the reflectivities and layer structures of Mo/Si multilayers with and without barrier layers were investigated using X-ray diffraction and transmission electron microscopy. The results show that, for applications using intense soft X-ray beams, Mo/Si multilayers with interleaved carbon barrier layers are better mirrors than Mo/Si multilayers because they have much better heat resistance and almost the same soft X-ray reflectivity as the Mo/Si multilayers.
Advanced Capabilities for Future Light Sources
Authors: Kim Kwang-Je
Published: July 2004

Methods to extend the capabilities of light sources beyond those available at the current generation synchrotron radiation sources based on undulators in electron storage rings are discussed. Taking advantage of the radiation–particle interaction and/or the availability of high-power ultrashort optical lasers, it is possible to develop sources with higher brightness, smaller temporal resolution, or higher photon energy. This paper is a summary of some of these schemes, with an emphasis on new ideas rather than on a comprehensive review.
DAFS measurements using the image-plate Weissenberg method
Authors: Sugioka Naoya , Matsumoto Kenji , Tanaka Masahiko , Mori Takeharu , Sasaki Satoshi
Published: July 2004

An instrumental technique for DAFS measurements which can provide site-specific information is proposed. The approach uses (i) focusing optics with parabolic mirrors and a double-crystal monochromator, (ii) the Laue and Bragg settings and (iii) data collection by the image-plate Weissenberg method. Six image exposures are recorded per plate at five intrinsic energies and one reference energy. The single-crystal measurements were performed at the Co K-absorption edge, and the 200, 220 and 311 reflections of CoO and 511 and 911 reflections of Co3O4 were used for analysis. The regression analysis of χ(k), Fourier transforms of k
3χ(k) and back-Fourier filtering have been performed.
A new image-plate reader for various sizes and shapes
Authors: Takagi Yasuo , Kikuchi Toshiharu , Katayama Chuji
Published: July 2004

A new image-plate reader which can read image plates (IPs) having various sizes and shapes has been developed. The machine consists of a rotating laser head to induce luminescence photons from IPs and a porous cylindrical holder made of a composite of cast iron and porous ceramic – so-called `breathnite'. Image plates can be fixed onto the inner surface of the cylindrical holder by evacuating the outer surface through a vacuum chamber with a mechanical pump. Image plates having various shapes and sizes up to 400 × 400 mm can be fixed without covering the open surface on the cylinder. In spite of such flexibility to various applications, the reader produces competitive performances compared with other commercial readers.
X-ray polarimetry with the microstrip gas chamber
Authors: Nishi Y. , Aoki S. , Ochi A. , Tanimori T. , Takahashi T. , Ueda Y. , Okada K.
Published: July 2004

A two-dimensional microstrip gas chamber (MSGC) with a 5 cm × 5 cm detection area has been developed. It has 254 anodes and 255 back strips, both with 200 µm pitches. Using this MSGC, linear polarization of X-rays was successfully measured in the energy range 6–14 keV. In addition, the performance of the MSGC as an X-ray imaging polarimeter has been simulated using the EGS4 program (Electron Gamma Shower, Version 4) modified for this purpose. In this article, the results of both the polarization measurement and the simulation are reported.
The gas-phase photoemission beamline at Elettra
Authors: Prince K. C. , Blyth R. R. , Delaunay R. , Zitnik M. , Krempasky J. , Slezak J. , Camilloni R. , Avaldi L. , Coreno M. , Stefani G. , Furlani C. , de Simone M. , Stranges S.
Published: July 2004

This paper reports the present stage of commissioning of the gas-phase photoemission beamline at Elettra, Trieste. The beamline is designed for atomic and molecular science experiments with high-resolution and high-flux synchrotron radiation. It consists of an undulator source, variable-angle spherical-grating monochromator and two experimental stations. The design value of the energy range is 20 to 800 eV with a specified resolving power of over 10000. The procedure adopted for calibration of this type of monochromator is discussed. At present a resolving power up to 20000 and a range up to 900 eV have been measured. Absorption spectra taken at the argon L
II,III-edge and at the nitrogen, oxygen and neon K-edges are as sharp as, or sharper than, any reported in the literature. The instrumental broadening is well below the natural line-width making it difficult to quantify the resolution; this problem is discussed.
SINBAD, a brilliant IR source from the DAΦNE storage ring
Authors: Marcelli Augusto , Burattini Emilio , Mencuccini Corrado , Calvani Paolo , Nucara Alessandro , Lupi Stefano , Sanchez Del Rio Manuel
Published: July 2004

SINBAD is the Italian IR synchrotron radiation beamline, designed to work at wavelengths greater than 10 µm. It is being installed on DAΦNE, a new collider that is designed to work at 0.51 GeV with a beam current up to 5 A. Due to such a high current, the IR extracted from a bending magnet will be more brilliant than that of a black body at 2000 K by two orders of magnitude at 100 µm. The beamline optical system, projected by ray-tracing simulation, consists of six mirrors that first focus the radiation on a wedged CVD diamond-film window and then transfer the collimated beam to the experimental area where a Michelson interferometer will be installed.
Manufacturing advances in large grazing-incidence optics
Authors: Bender John , Anspach Joel , Tonnessen Tom
Published: July 2004

The fabrication of large grazing-incidence mirrors imposes needs for special fabrication and coating equipment, facilities, and raw materials. The economic realization of such optics has been readily accomplished through close interactions between the mirror users, the fabricator and the manufacturer of the raw material designated as mirror substrate. The manufacture and delivery of a 1.4 m flat and 1.0 m conical mirror are used to provide examples of recently demonstrated manufacturing technologies and effective interactions between participating organizations.
A versatile X-ray diffraction station at LNLS (Brazil)
Authors: Cusatis Cesar , Kobayashi Franco Margareth , Kakuno Edson , Giles Carlos , Morelhão Sergio , Mello Vivaldo , Mazzaro Irineu
Published: July 2004

Versatility was a major consideration in the project to provide an X-ray diffraction station at LNLS. At least two techniques are possible at the station: powder diffraction and multiple single-crystal diffraction. A two-crystal monochromator based on monolithic elastic translators, developed at LNLS, with sagittal focusing by the second crystal, allows 10 mrad of a ≥2 keV monochromatic beam to be used on the diffractometer. The station is equipped with a fast scintillation detector, imaging plates, a high-energy-resolution pin-diode detector, an ionization chamber and a high-angular-resolution soller slit. The data collection and control hardware and software were also developed at LNLS. The θ–2θ goniometry for powder diffraction on this 1 m-diameter diffractometer is based on commercial rotation tables. The multiple single-crystal goniometry is realized by an independent elastic axis driven by differential micrometers for both high- and low-resolution angular movements. At least four independent axes can be positioned as necessary on the diffractometer table. Powder diffractograms and double-crystal rocking curves collected with the synchrotron beam show the expected quality.
A simple accurate method of alignment of beamline optics with the use of EUV multilayer polarizers
Authors: Yamamoto Masaki , Furudate Minaji , Yanagihara Mihiro , Kimura Hiroaki
Published: July 2004

A simple alignment method is proposed, which enables the alignment of beamline optics of a bending section accurately, relying on the linear state of polarization of synchrotron orbital radiation rather than the beam intensity. The method utilizes extreme UV (EUV) multilayers as a compact polarization monitor detecting unwanted vertical polarization components. The proposed method was found to be far more sensitive than that relying on the maximum intensity. Another advantage is the insensitivity to surface contamination, such as an irradiation mark on the mirror degrading reflectance. A design example is presented for use around a photon energy of 370 eV along with an experimental example at a photon energy of 97 eV.
Development of a MicroStrip Gas Chamber as a Time-Resolved Area Detector
Authors: Tanimori Toru , Aoki Shunsuke , Nishi Yuji , Ochi Atsuhiko
Published: July 2004

A two-dimensional microstrip gas chamber (MSGC) has been developed with a 10 cm-square detection area and an ultrafast read-out system. The MSGC was made using multi-chip module (MCM) technology, and has a very thin substrate of 17 µm and many anodes and back strips, both with 200 µm pitches. The new read-out system, in which the hit addresses of the electrodes were sequentially encoded to the hit positions by a synchronous clock, handles data rates of up to 107 events s−1 from MSGCs. This enables the acquisition of fast and sequential digital images. Furthermore, since the MSGC is a real photon-counting detector, the timing of the photons, to an accuracy of a few tens of nanoseconds, and energy can be recorded. Here, the performance of the MSGC system as a real-time area detector is reported, and the abilities of this system are discussed.
Plane-grating monochromator at BESSY II using collimated light
Authors: Follath R. , Senf F. , Gudat W.
Published: July 2004

At the German synchrotron radiation facility BESSY II, the VUV photon energy range between 15 and 600 eV is covered by the first, third and fifth harmonics of the U125 undulator. The beamline connected to this source is a plane-grating monochromator (PGM) with a variable deviation angle. The plane grating is illuminated by collimated radiation, allowing very flexible use of the monochromator. Depending on users' demands, it can be operated at high spectral resolution, high-order suppression or in high-flux mode, simply by software control.
Design and feasibility of quick EXAFS scans for a `broomstick' double-crystal monochromator at PLS beamline
Authors: Lee J. M. , Sung Nark-Eon , Park Jeong-Kweon , Yoon Jah-Geol , Kim Jin-Hong , Choi Man-Ho , Lee Ki-Bong
Published: July 2004

A data-collection technique for quick extended X-ray absorption fine-structure spectroscopy (QEXAFS) was developed with a new `broomstick' double-crystal monochromator, which has been installed for X-ray absorption fine-structure (XAFS) applications at the Pohang Light Source. The monochromator operates in a fixed-exit scan mode as the Bragg angle is varied from 8 to 80°, corresponding to 2–14 keV, using an Si(111) crystal. The monochromator scan capability was investigated by analysing EXAFS data quality from step-scan and from continuous rotation of the Bragg crystal reflection angle. In our fast continuous-scan design, the electronic pulsing speed of the step motor is adjustable to avoid the monochromatic beam instability caused by serious mechanical resonance. The feasibility of QEXAFS scanning is demonstrated by a typical EXAFS scan (e.g. 1 keV range) being taken within 1 min.
X-ray triple refraction and triple absorption in a cobalt-complex crystal
Authors: Okitsu Kouhei , Ueji Yoshinori , Oguchi Takuyo , Hasegawa Yuji , Ohashi Yuji , Amemiya Yoshiyuki
Published: July 2004

X-ray triple refraction and triple absorption have been quantitatively measured for the first time. The samples were (100)-, (010)- and (001)-oriented plates of a cobalt-complex monoclinic crystal. The apparatus used was an energy-tunable X-ray polarimeter with a phase retarder. The X-ray energy was scanned over a range of 150 eV near the cobalt K-absorption edge. Both the spectra of ellipticity and rotation of polarization were completely different for each crystal plate, which revealed that the biaxial crystal had three refractive indices and three absorption coefficients in the X-ray region. The Kramers–Kronig relation between the real and imaginary parts of the dielectric anisotropy has been quantitatively confirmed for all three different orientations.
X-ray linear birefringence and linear dichroism in a cobalt crystal measured with a tunable X-ray polarimeter
Authors: Okitsu Kouhei , Oguchi Takuyo , Maruyama Hiroshi , Amemiya Yoshiyuki
Published: July 2004

X-ray linear birefringence and linear dichroism spectra have been measured simultaneously and quantitatively for the first time. The sample was a hexagonal cobalt single-crystal foil. The apparatus used was an energy-tunable X-ray polarimeter, consisting of a polarizer, a phase retarder and an analyser. The X-ray energy was scanned over a range of 350 eV near the K-absorption edge. The Kramers–Kronig relation between the refraction and absorption anisotropy has been confirmed on an absolute scale. The phase-difference sensitivity of the polarimeter as a polarization inferometer is as small as 2π/10000, which is about 100 times smaller than that of the Bonse–Hart inferometer.
A uniformly cleaved epitaxically grown diamond crystal for synchrotron radiation
Authors: Shinohara Armando H. , Kamo Mutsukazu , Suzuki Carlos K.
Published: July 2004

A homoepitaxic single-crystal diamond (111) film grown by microwave-assisted chemical vapour deposition (CVD) and fractured along the [110] directions to form small triangles was investigated by X-ray double-crystal topography. The X-ray topographic image showed that all parts of the cleaved CVD diamond film sections uniformly reflected X-rays at the peak position of the rocking curve, which was measured in the Bragg case. Furthermore, no bending effect was observed and the CVD diamond film appeared to be more perfect than and showed higher integrated intensity than the natural diamond substrate.
Characterization of substrates for use in X-ray multilayer optics
Authors: Lodha G. S. , Yamashita K. , Haga K. , Kunieda H. , Nakajo N. , Nakamura N. , Tamura K. , Tawara Y. , Bennett J. M. , Yu J. , Namba Y.
Published: July 2004

The optical performance of platinum–carbon multilayers deposited onto different substrates has been examined. Specular reflectivity and non-specular diffuse scattering were measured to study the replication of substrate roughness into the multilayer structure. Surface topography was measured before and after deposition using a scanning probe microscope and a mechanical profiler.
Generalized grazing-incidence-angle X-ray diffraction (G-GIXD) using image plates
Authors: Takagi Yasuo , Kimura Masao
Published: July 2004

A new and more `generalized' grazing-incidence-angle X-ray diffraction (G-GIXD) method which enables simultaneous measurements both of in- and out-of-plane diffraction images from surface and interface structures has been developed. While the method uses grazing-incidence-angle X-rays like synchrotron radiation as an incident beam in the same manner as in `traditional' GIXD, two-dimensional (area) detectors like image plates and a spherical-type goniometer are used as the data-collection system. In this way, diffraction images both in the Seemann–Bohlin (out-of-plane) and GIXD geometry (in-plane) can be measured simultaneously without scanning the detectors. The method can be applied not only to the analysis of the in-plane crystal structure of epitaxically grown thin films, but also to more general research topics like the structural analysis of polycrystalline mixed phases of thin surface and interface layers.
Precision goniometer equipped with a 22-bit absolute rotary encoder
Authors: Xiaowei Zhang , Ando Masami , Jidong Wang
Published: July 2004

The calibration of a compact precision goniometer equipped with a 22-bit absolute rotary encoder is presented. The goniometer is a modified Huber 410 goniometer: the diffraction angles can be coarsely generated by a stepping-motor-driven worm gear and precisely interpolated by a piezoactuator-driven tangent arm. The angular accuracy of the precision rotary stage was evaluated with an autocollimator. It was shown that the deviation from circularity of the rolling bearing utilized in the precision rotary stage restricts the angular positioning accuracy of the goniometer, and results in an angular accuracy ten times larger than the angular resolution of 0.01 arcsec. The 22-bit encoder was calibrated by an incremental rotary encoder. It became evident that the accuracy of the absolute encoder is approximately 18 bit due to systematic errors.
First performance assessment of the small-angle X-ray scattering beamline at ELETTRA
Authors: Amenitsch H. , Rappolt M. , Kriechbaum M. , Mio H. , Laggner P. , Bernstorff S.
Published: July 2004

The double-focusing high-flux wiggler beamline dedicated to small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) at ELETTRA has gone into user operation recently. It has been designed specifically for time-resolved studies of non-crystalline and fibrous materials in the submillisecond time scale, and has been optimized for small-angle scattering measurements. An overview of the beamline status and of some representative results, highlighting the performance of the SAXS beamline, are given.
The commissioning of a flexible low-cost multipurpose X-ray beamline at SRRC
Authors: Lee Chih-Hao , Hwang Ching-Shiang , Tseng Poh-Kun , Tseng Huan-Chi , Yu Kuan-Li , Su Wei-Chia , Chen June-Rong , Lin Tsang-Lang , Chang Szu-Li
Published: July 2004

A low-cost multipurpose X-ray beamline has been commissioned at the bending magnet B15 of the Synchrotron Radiation Research Center (SRRC). The beamline is constructed in such a way to accommodate the various needs of small research consortia, from universities or research institutes, whose requirements of a beamline facility are quite diverse while under limited funding support. Flexibility is the special feature of this beamline. It is capable of performing quick test measurements without a prolonged reviewing process. Switching between different techniques, such as white-beam irradiation, EXAFS and X-ray scattering, can be achieved within 1 h. Novel experiments, such as energy-dispersive small-angle scattering experiments and energy-dispersive reflectivity measurements, can also be performed.
Focusing Optics for High-Energy X-ray Diffraction
Authors: Lienert U. , Schulze C. , Honkimäki V. , Tschentscher Th. , Garbe S. , Hignette O. , Horsewell A. , Lingham M. , Poulsen H. F. , Thomsen N. B. , Ziegler E.
Published: July 2004

Novel focusing optical devices have been developed for synchrotron radiation in the energy range 40–100 keV. Firstly, a narrow-band-pass focusing energy-tuneable fixed-exit monochromator was constructed by combining meridionally bent Laue and Bragg crystals. Dispersion compensation was applied to retain the high momentum resolution despite the beam divergence caused by the focusing. Next, microfocusing was achieved by a bent multilayer arranged behind the crystal monochromator and alternatively by a bent Laue crystal. A 1.2 µm-high line focus was obtained at 90 keV. The properties of the different set-ups are described and potential applications are discussed. First experiments were performed, investigating with high spatial resolution the residual strain gradients in layered polycrystalline materials. The results underline that focused high-energy synchrotron radiation can provide unique information on the mesoscopic scale to the materials scientist, complementary to existing techniques based on conventional X-ray sources, neutron scattering or electron microscopy.
New transmission-type X-ray filters consisting of amorphous multilayer films
Authors: Takagi Yasuo , Imafuku Muneyuki
Published: July 2004

New transmission-type X-ray filters have been developed. The filters consist of X-ray-amorphous metal (less than 30 Å)/metalloid (∼10 Å) multilayer films sputter-deposited on X-ray-transparent polymer substrates. Such metal/metalloid multilayer films show only very broad diffraction peaks, since the metal and metalloid layers forming the multilayer films are usually X-ray amorphous if the layers are sufficiently thin. The filters use the wavelength-dependent absorption phenomena near absorption edges of elements to reduce the intensity of transmitted X-rays, without generating any crystalline sharp peaks which cause serious problems in experiments such as fluorescence XAFS measurements. The multilayer-film filters were prepared by a multi-target magnetron sputtering deposition technique, paying special attention to the homogeneity of the layer thickness by spinning substrates of the films. The filters are useful in reducing the intensity of undesirable fluorescence emissions and improving the signal-to-background ratios of data acquired in various measurements using a solid-state detector.
Material analysis end-station of the Hyogo-ken beamline at SPring-8
Authors: Kaneyoshi T. , Ishihara T. , Yoshioka H. , Motoyama M. , Fukushima S. , Hayashi K. , Kawai J. , Taniguchi K. , Hayakawa S. , Gohshi Y.
Published: July 2004

Plans to construct surface-analysis equipment which will be placed on beamline BL24XU of SPring-8 are presented. There are three experimental hutches in BL24XU, which are available simultaneously by using diamond monochromators as beam splitters. The purpose of the surface-analysis equipment is the simultaneous measurement of fluorescent and diffracted X-rays in grazing-incidence geometry. The instrument is equipped with a solid-state detector (SSD) and a flat position-sensitive proportional counter (PSPC) combined with analysing crystals for X-ray fluorescence (XRF) analysis. A curved PSPC and the goniometer that mounts the SSD used for XRF are also installed for X-ray diffraction. X-ray fluorescence holography and polarized X-ray emission spectroscopy modes are available, so three-dimensional images of atomic configurations and also the anisotropic structure of materials will be studied.
Mössbauer surface-guided waves in media with space modulation of Mössbauer isotope concentration
Authors: Belyakov V. A. , Aivazian Yu. M.
Published: July 2004

Rapid progress in Mössbauer spectroscopy combined with synchrotron radiation (SR) makes it urgent to study the interaction of SR with structures which have a space modulation of the Mössbauer isotope concentration, and thereby to reveal new effects in this interaction. Presented here are theoretical studies of the Mössbauer surface-guided mode (MSGM) in such media. MSGMs are analogous to the well known surface-guided electromagnetic waves (SGEW) in periodic media. However, because of their resonant interaction with Mössbauer nuclei they reveal some qualitative peculiarities compared with the case of conventional SGEW. The MSGMs for the case of purely nuclear Bragg scattering of quanta at a plane interface between a homogeneous medium and a medium with a periodic space modulation of the Mössbauer isotope concentration are investigated theoretically. The conditions of MSGM existence and allowed spectral intervals for the MSGM and their dependence on the period of space modulation and the degree of medium enrichment by the Mössbauer isotope are found. It is shown that the allowed interval of the MSGM frequencies is located at one side relative to the exact Mössbauer resonant frequency. Its width is of the order of the Mössbauer line width and can be effectively changed by the variation of the modulation period or the Mössbauer isotope concentration. For the MSGM frequencies close to the boundary of the MSGM existence interval, the attenuation of an MSGM propagating along the interface may be essentially lower than the conventional Mössbauer radiation attenuation in the same medium. The possibilities of SR Mössbauer filtration by means of MSGM are briefly discussed.
Two recent developments in XMCD
Authors: Baudelet F. , Dubuisson J. M. , Hébert C. , Créoff C. , Pointal L. , Andouard R. , Odin S. , Dartyge E. , Krill G. , Giorgetti C. , Chervin J. C. , Itié J. P. , Polian A. , Fontaine A. , Pizzini S. , Kappler J. P.
Published: July 2004

This paper reports on two new technical developments concerning sample environments for X-ray magnetic circular dichroism (XMCD). The first measurements under high pressures of up to 30 GPa are described. The difficulties of combining the techniques of high pressure and XMCD are commented on. The second development involves the use of a fast-switching magnetic field. A new superconducting device is used to perform XMCD measurements on paramagnetic compounds in magnetic fields of up to 6 T. The small amplitude of the XMCD signal imposes, for a given signal-to-noise ratio, a noise less than a few 10−5. The signal-to-noise ratio is improved by the use of a series of acquisitions, switching the magnetic field between each acquisition. A very fast switching mechanism has been built based on mechanical rotation of a superconducting coil, with the sample kept in place inside the coil. The XMCD signals at the L
II,III-edges of paramagnetic rare-earth compounds have been measured at 4.5 K in fields of up to 6 T with a switching time of 11 s.
The influence of interface roughness on Mössbauer filtration of synchrotron radiation at an isotope interface
Authors: Belyakov V. A. , Semenov S. V.
Published: July 2004

The influence of interface irregularities on synchrotron radiation Mössbauer filtration at an isotope interface is examined theoretically. Calculations are performed for a random-roughness interface model for a 56Fe/57Fe isotope interface. The analysis shows that, despite a drop in the efficiency in the real structures compared with the idealized structures, the efficiency of Mössbauer filtration of synchrotron radiation remains high enough to ensure a successful experiment. In particular it was found that, as well as a regular saw-like profile of the external interface, a randomly rough profile of the external interface may also be used in the Mössbauer filtration experiment if the roughness parameters satisfy certain demands.
One- and Two-Coordinate Detectors in BINP
Authors: Aulchenko Vladimir M. , Baru Semen E. , Dubrovin Mihail S. , Savinov Gennady A. , Shekhtman Lev I. , Titov Vitaly M. , Velikzhanin Yury S. , Ancharov Alexey I. , Gaponov Yury A. , Evdokov Oleg V. , Tolochko Boris P.
Published: July 2004

One- and two-coordinate detectors with proportional chambers developed at the Budker Institute of Nuclear Physics (BINP) are presented. The parallax-free 10 MHz one-coordinate OD-3.1 and OD-3.2 detectors are used in synchrotron radiation powder diffraction and SAXS experiments. The two-coordinate DED-3 detector with a multiwire proportional chamber (MWPC) is used in Laue diffraction. The latest modification of this detector, DED-5, with a working area of 384 × 384 mm, is briefly described. The micro-strip detector prototype MSGC-100 has passed test synchrotron radiation experiments and the next modification (MSGC-500), with 500 channels for high energy, is under construction. The one-coordinate MWPC OD-160 detector, with an angle aperture of 160° and a count rate of 3.3 GHz, is under construction. It will be used for high-resolution powder diffraction. Two types of gas chamber will be used: L for low energies (5–30 keV) and H for high energies (30–70 keV). A 16° section with an H-chamber has been produced and tested on the synchrotron radiation beamline.
X-ray absorption beamline at the Mitsubishi compact storage ring
Authors: Uehara Yasushi , Okajima Toshihiro , Nakanishi Tetsuya , Kurokawa Hiroshi , Baba Fumiaki
Published: July 2004

Beamline #5 (BL#5) at the Mitsubishi compact storage ring (MELCO-SR) is a beamline designed to perform X-ray absorption experiments in the 1–5 keV energy range. MELCO-SR is a racetrack-type storage ring with compact superconducting magnets, which is operated at 600 MeV, mainly for X-ray lithography experiments. As the ring is set in a shield wall of 2 m thickness, a point just outside the shield wall of BL#5 is located at 6.8 m from the source point. A small toroidal mirror, located inside the shield wall at 3.4 m from the source, focuses the beam vertically and horizontally onto the 7.3 m point. This simple optical configuration allows us to bring the source point outside of the shield wall, and to collect about 10 mrad horizontally and maintain small footprints on the monochromator crystal. A new `Cowan type' monochromator, located at 7.4 m from the source and selected for simplicity of design and for stability, will provide a bright high-resolution and stable X-ray beam for use in the X-ray spectroscopy of electronic materials in MELCO.
High-Energy Inelastic-Scattering Beamline for Electron Momentum Density Study
Authors: Sakurai Y.
Published: July 2004

The advent of synchrotron radiation sources for well polarized and high-energy X-rays offers new opportunities for exploiting Compton scattering spectroscopy as a tool for investigating the electronic and magnetic structures of materials. Recent high-resolution Compton scattering experiments show the unique capability for the study of Fermiology-related issues and electron–electron correlation effects. Intense, high-energy and circularly polarized X-ray sources have improved magnetic Compton scattering spectroscopy from the point of statistical accuracy and momentum resolution. As a next advance, a high-energy inelastic scattering beamline dedicated to Compton scattering spectroscopies is being constructed at SPring-8. The light source is an elliptic multipole wiggler with a periodic length of 12 cm. The beamline includes two experimental stations: one is for high-resolution spectroscopy using 100–150 keV X-rays and the other is for magnetic Compton scattering experiments using circularly polarized 300 keV X-rays. The use of such high-energy X-rays makes it possible to carry out experiments efficiently on samples including heavier elements, such as high-T

c
superconductors and 4f and 5f magnetic materials.
High-spatial-resolution and real-time medical imaging using a high-sensitivity HARPICON camera
Authors: Umetani Keiji , Ueki Hironori , Takeda Tohoru , Itai Yuji , Mori Hidezo , Tanaka Etsuro , Uddin-Mohammed Minhaz , Shinozaki Yoshiro , Akisada Masayoshi , Sasaki Yasuhito
Published: July 2004

A HARPICONTM camera has been applied to a digital angiography system with fluorescent-screen optical-lens coupling. It uses avalanche multiplication in the photoconductive layer for high-sensitivity imaging. The limiting spatial resolutions in the 1050 scanning-line mode of the camera are about 30 and 50 µm at input field sizes of 20 × 20 and 50 × 50 mm on the screen, respectively. For high-speed imaging, the 525 scanning-line mode at a rate of 60 images s−1 can be selected. High-quality images of coronary arteries in dogs were obtained by intra-aortic coronary angiography and superselective coronary angiography using a single-energy X-ray above the iodine K-edge energy.
Time-resolved fluorescent X-ray interference
Authors: Sasaki Y. C. , Suzuki Y. , Yamanashi H. , Arai A. , Yanagihara M.
Published: July 2004

A fluorescent X-ray interference method can effectively measure nanometer-level conformational changes for non-crystallized molecules and proteins in aqueous conditions. The time-resolved technique can be used to obtain information about the dynamics of molecules and proteins. Instrumentation for time-resolved fluorescent X-ray interference has been designed. A typical interference-fringe pattern was observed with approximately 3 s of X-ray exposure time from K-fluorescent X-rays emitted from a Zn monoatomic layer on an Rh substrate. The primary X-ray beam was polychromed with a mirror for total external reflection of X-rays and was tuned to an energy level at which only Zn K radiation became optimally excited. The glancing angle of the primary X-ray beam was fixed at a glancing angle at which the total intensity of K-fluorescent X-rays emitted from Zn atoms corresponded to the maximum value. The fluorescent X-ray interference fringes were monitored with an imaging plate (IP) as a non-energy-dispersive two-dimensional detector. The exposed interference fringes on the IP were integrated along the direction of the fringes. The integrated fringes were in close agreement with a theoretical estimate based on the interference among transmitted and reflected waves at interfaces in the sample.
A Prospect and Retrospect – the Japanese Case
Authors: Sasaki Taizo
Published: July 2004

The early through recent history of synchrotron radiation research in Japan, since the initial efforts in 1962, is reviewed. Following a period of parasitic use of an electron synchrotron, Japanese users attempted to build a storage ring as a dedicated soft X-ray source, which was completed in 1974. It opened up a new era of second-generation synchrotron radiation research. The Photon Factory, a dedicated X-ray source commissioned in 1982, provided a much wider research area as well as a number of technical innovations, among which insertion devices brought the further prospect of significant improvements in the properties of sources. As a consequence, the new concept of a light source oriented towards full exploitation of insertion devices, or the idea of a third-generation source, was created. The motivations and developments which led to Spring-8, a third-generation Japanese X-ray source that is currently being commissioned, will be reviewed briefly.
The EXAFS family tree: a personal history of the development of extended X-ray absorption fine structure
Authors: Lytle Farrel W.
Published: July 2004

This paper reviews the history of X-ray absorption spectroscopy (XAS) beginning with the first observation of an absorption edge, through the development of the modern theory and data inversion by the Fourier transform. I stop with my first trip to a synchrotron X-ray source. The study of XAS began at an exciting time for science. Wave mechanics, X-ray diffraction, X-ray scattering from non-crystalline materials experiments developed in parallel with XAS. However, the difficulty of obtaining data from conventional X-ray tubes limited the field to a potentially interesting minor subject. Only with the advent of synchrotron radiation and arrival of modern theory in the 1970s did XAS become widely applicable to fields ranging from environmental to biological sciences. Early developments in experimental technique and theory are emphasized. Since I worked in both the before-synchrotron and after-synchrotron time frames, I had the opportunity to meet some of the early scientists. A number of historical vignettes and photographs of the scientists involved in the development of EXAFS are presented.
XAFS spectroscopy in catalysis research: AXAFS and shape resonances
Authors: Koningsberger Diek , Mojet Barbara L. , Miller Jeff , Ramaker Dave
Published: July 2004

Two new techniques in X-ray absorption spectroscopy (XAS) have recently been developed which provide previously unobtainable information on supported noble metal catalysts. Atomic X-ray absorption fine structure (AXAFS) provides direct information on the average changes in interatomic potential of the metal particles induced by metal-support effects. Changes in the interatomic potential can now be directly related to changes in catalytic reactivity. Analysis of shape resonances near the X-ray absorption edge provides information on the changes in the nature of the bonding of adsorbates (like hydrogen) to the metal cluster as induced by the properties of the support. The strong decrease in activity of supported platinum clusters for neo-pentane hydrogenolysis with increasing alkalinity of the support can be ascribed to a decrease in ionization potential of the metal particles directly influenced by the alkalinity of the support.
Electronic databases: the Indian scenario
Authors: Singh Anil , Gautam J.N.
Published: July 2004

Computer usage has become commonplace and there has been an increasing number of local efforts in organising indigenous information for individual and institutional utility. Access to information online or in CD‐ROM media is now just a matter of money; at the same time access to indigenous information has remained a challenging effort both for the user and the infomediary. Information services/products of all kinds are being generated by various agencies in the government, public and private sectors and are emerging out into the Indian information marketplace. There are a number of abstracting journals, which, in a natural process of migration, are now available in dual formats – print as well as machine readable. Besides bibliographic information, service providers are generating factual information – as directories of all descriptions, financial and commercial data, full texts of case laws, export‐import policy and so on. In this paper an attempt is made to present an overview of some of the important electronic databases developed in India or on Indian topics.
Bringing collections to life, digitising local studies and special collections: the COLLAGE project
Authors: Leslie Fiona
Published: July 2004

The Corporation of London Library and Art Gallery Electronic (COLLAGE) identified the relative inaccessibility of their extensive visual collections – the prints, maps, photographs and ephemera held by Guildhall Library and the 4,000 plus works of art held by the Guildhall Art Gallery – as a challenge. Direct consultation with staff and existing users suggested that digitisation could enrich the catalogue and ensure wider access to the resources while ensuring the preservation of the originals for future generations. The public user interface is already online and, as resource discovery is the primary driver for the project, a direct link between COLLAGE and the library OPAC is planned to allow users to search “traditional” resources seamlessly alongside the images.
The effect of system response time on visual search in Web pages
Authors: van Schaik Paul , Ling Jonathan
Published: July 2004

Previous research has highlighted the importance of system response time (SRT) for Web usability. In the present study, this parameter was studied using a choice reaction task to assess the effect on both performance and subjective measures. Results showed that SRT variability had no effect on usability when using text displays and, although Web experience increased speed of task performance, this did not affect perceptions of SRT. Presents implications for Web server design and future research into SRT.
Applicability of a brand trust scale across product categories
Authors: Delgado‐Ballester Elena
Published: July 2004

Despite increased attention and relevance drawn by trust as a key characteristic required for relationship marketing success, it has seldom been explicitly examined in end‐consumer studies, especially those concerning consumer‐brand domain. Consequently, no current scale exists to measure trust in a brand setting. This research presents the results of two studies conducted to develop a scale to measure brand trust, which is called brand trust scale (BTS), and analyse the equivalence of its psychometric characteristics when the scale is used in two different product categories. The findings derived from two random samples of consumers give empirical support for the consistency and validity of the scale developed, and the distinction of two main dimensions on the concept: brand reliability and brand intentions. The results also provide empirical evidence of the scale invariance, meaning that consumers of two different products interpreted brand trust in the same way.
The relationship between power and dependence in marketing channels
Authors: Zhuang Guijun , Zhou Nan
Published: July 2004

This paper studies the causal relationship between dependence and power in the context of marketing channels in China in the setting of department stores and their suppliers. The hypothesized relationship that a channel member's power is derived from the other's dependence in the channel dyad, which is based on existing Western literature on channel behavior, did not fit well with our data. Some dimensions of dependence did not have a significant influence on channel members’ perception of power. The empirical data fits better with a reversed relationship inferred from the Chinese psychoculture.
Sourcing strategies of facilities management
Authors: Hui Encon Y.Y. , Tsang Albert H.C.
Published: July 2004

In this study, four sourcing strategies are identified in the delivery of maintenance service in facilities management, namely in‐sourcing, out‐tasking, outsourcing for cost saving, and outsourcing for capability. Since each of these strategies has merits under specific circumstances, a framework for the selection of appropriate sourcing strategy in particular situations is presented. This framework, which takes into consideration both the scope and purpose of the sourcing decision, was developed on the basis of results of earlier research and has been validated by the findings obtained from interviews with practitioners in exemplary organizations. This paper also provides guidelines for implementing the selected sourcing option, along with discussion of the related strategic and operational issues.
Rapid Report
Authors: Ørtenblad Niels , Stephenson D. George
Published: July 2004

Single skeletal muscle fibres from rat and cane toad were mechanically skinned and stimulated either electrically by initiating action potentials in the sealed transverse (t‐) tubular system or by ion substitution causing depolarisation of the t‐system to pre‐determined levels. Depression of mitochondrial ATP‐producing function with three diverse mitochondrial function antagonists (azide: 1–10 mm; oligomycin 1 μg ml−1 and carbonyl cyanide 4‐trifluoromethoxyphenylhydrazone (FCCP) 1 μm), under conditions in which the cytosolic ATP was maintained high and constant, invariably reduced the excitability of rat fibres but had no obvious effect on the excitability of toad fibres, where mitochondria are less abundant and differently located. The reduction in excitability linked to mitochondria in rat fibres appears to be caused by depolarisation of the sealed t‐system membrane. These observations suggest that mitochondria can regulate the functional state of mammalian muscle cells and have important implications for understanding how the balance between ATP utilisation and ATP production is regulated at the cellular level in general and in mammalian skeletal muscle fibres in particular.
The Hodgkin–Huxley–Katz Prize Lecture
Authors: Meinrenken Christoph J. , Borst J. Gerard G. , Sakmann Bert
Published: July 2004

During the last decade, advances in experimental techniques and quantitative modelling have resulted in the development of the calyx of Held as one of the best preparations in which to study synaptic transmission. Here we review some of these advances, including simultaneous recording of pre‐ and postsynaptic currents, measuring the Ca2+ sensitivity of transmitter release, reconstructing the 3‐D anatomy at the electron microscope (EM) level, and modelling the buffered diffusion of Ca2+ in the nerve terminal. An important outcome of these studies is an improved understanding of the Ca2+ signal that controls phasic transmitter release. This article illustrates the spatial and temporal aspects of the three main steps in the presynaptic signalling cascade: Ca2+ influx through voltage‐gated calcium channels, buffered Ca2+ diffusion from the channels to releasable vesicles, and activation of the Ca2+ sensor for release. Particular emphasis is placed on how presynaptic Ca2+ buffers affect the Ca2+ signal and thus the amplitude and time course of the release probability. Since many aspects of the signalling cascade were first conceived with reference to the squid giant presynaptic terminal, we include comparisons with the squid model and revisit some of its implications. Whilst the characteristics of buffered Ca2+ diffusion presented here are based on the calyx of Held, we demonstrate the circumstances under which they may be valid for other nerve terminals at mammalian CNS synapses.
Rapid Report
Authors: Rosenmeier Jaya B. , Dinenno Frank A. , Fritzlar Sandy J. , Joyner Michael J.
Published: July 2004

Sympathetic vasoconstriction is blunted in the vascular beds of contracting skeletal muscles. We sought to determine whether this blunted vasoconstriction is specific for post‐junctional α1‐ or α2‐adrenergic receptors. We measured forearm blood flow (Doppler ultrasound) and calculated the vascular conductance (FVC) responses to brachial artery infusions of tyramine (which evokes endogenous noradrenaline release), phenylephrine (an α1agonist) and clonidine (an α2agonist) in 10 healthy men during rhythmic handgrip exercise (10‐15 % of maximum) and during a control non‐exercise vasodilator condition (intra‐arterial adenosine). Steady‐state FVC during exercise and adenosine was similar in all trials (range: 243‐272 and 234‐263 ml min−1(100 mmHg)−1, respectively;P> 0.5). During exercise the percentage reductions in FVC in response to tyramine (−24 ± 7vs.−55 ± 6 %), phenylephrine (−12 ± 8vs.−37 ± 8 %) and clonidine (−17 ± 6vs.−49 ± 4 %) were significantly less compared with adenosine (allP< 0.05). The magnitude of the blunted vasoconstrictor responses was similar for both receptor subtypes. These findings are in contrast to those from studies in animals demonstrating that α2‐adrenergic receptor‐mediated vasoconstrictor responses are much more sensitive to contraction‐induced inhibition than α1‐mediated responses. We conclude that vasoconstrictor responses mediated via both post‐junctional α1‐ and α2‐adrenergic receptors are blunted in contracting human skeletal muscles.