bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of X-ray photoemission electron microscopy (X-PEEM) at the SRS
Authors: Smith A. D. , Cressey G. , Schofield P. F. , Cressey B. A.
Published: July 2004

The use of synchrotron radiation sources for X-ray spectroscopy is a well known and developed field. The majority of applications, however, have been limited to studies of materials containing only a single phase of the element of interest. Owing to limited availability of suitable instrumentation, the study of materials comprising intergrowths of different phases has presented difficulties in analysis. The majority of natural materials, including mineralogical samples, fall into this category. However, by applying the technique of photoemission electron microscopy (PEEM) to view the X-ray stimulated photoemission generated at an absorption edge, micro-area-selectable spectroscopy becomes possible. An instrument for X-ray PEEM (X-PEEM) is being developed at the Daresbury SRS and this paper shows how it can be used to obtain characteristic L-edge XANES spectra from finely intergrown iron oxide minerals.
Studies on intracellular structures of COS cells by X-ray microscopy
Authors: Yamamoto Akitsugu , Masaki Ryuichi , Guttmann Peter , Schmahl Günter , Kihara Hiroshi
Published: July 2004

COS-7 cells, fixed with glutaraldehyde, were studied using the transmission X-ray microscope at the electron storage ring BESSY, Berlin. The border of the cell, the nucleus, nucleoli and mitochondria of the cells were clearly visualized with the X-ray microscope. In addition, we found many X-ray dense granules preferentially located around the nucleus. Electron microscopy showed that numerous multivesicular bodies, whose structures belong to the endosome–lysosomal system, were present around the nucleus. The size and localization patterns of the X-ray dense granules were quite similar to those of multivesicular bodies. These results strongly suggest that the X-ray dense granules are multivesicular bodies.
Phase transitions of CdS microcrystals under high pressure
Authors: Nanba T. , Muneyasu M. , Hiraoka N. , Kaga S. , Williams G. P. , Shimomura O. , Adachi T.
Published: July 2004

The experiment under high pressure using a diamond anvil cell (DAC) requires the utilization of synchrotron radiation. High-pressure experiments were performed using a DAC on CdS microcrystals, both in the far-IR and in the X-ray regions, in order to study the lattice dynamics and lattice stability concerned with the phase transitions. From these experiments, experimental evidence is presented indicating that a CdS microcrystal of smaller diameter shows a higher transition pressure for lattice transformation under pressure. The origin of such an increase in the transition pressure in the microcrystals is discussed in relation to the surface tension.
An additional axis for the surface X-ray diffractometer
Authors: Takahasi Masamitu , Mizuki Jun'ichiro
Published: July 2004

A new surface X-ray diffractometer based on a κ-type diffractometer will be installed in BL14B1, SPring-8. This diffractometer has an additional axis on its detector arm for rotating the receiving slit about the normal of the slit plane, in addition to two axes for positioning the detector. This additional axis is founded on the consideration of the correction factor which has been derived so as to be valid for the z-axis mode measurement using any incoming and outgoing angles of the X-ray beam. The rotational slit allows accurate measurement of the surface structure factor up to large perpendicular momentum transfer.
X-ray characterization of α-Fe2O3 single crystals containing 2.2% and 95% 57Fe
Authors: Zhao J. Y. , Zhang X.-W. , Ando M. , Yoda Y. , Kikuta S. , Takei H.
Published: July 2004

α-Fe2O3 single crystals containing 2.2% and 95% 57Fe isotopes were characterized by means of X-ray topography, the diffraction rocking curve and the integrated intensity. These crystals were revealed to be nearly perfect and suitable for a further nuclear-resonant Bragg-scattering study.
SPring-8 beamline control system
Authors: Ohata Toru , Konishi Hiroyuki , Kimura Hiroaki , Furukawa Yukito , Tamasaku Kenji , Nakatani Takeshi , Tanabe Toshiya , Matsumoto Norimasa , Ishii Miho , Ishikawa Tetsuya
Published: July 2004

The SPring-8 beamline control system is now taking part in the control of the insertion device (ID), front end, beam transportation channel and all interlock systems of the beamline: it will supply a highly standardized environment of apparatus control for collaborative researchers. In particular, ID operation is very important in a third-generation synchrotron light source facility. It is also very important to consider the security system because the ID is part of the storage ring and is therefore governed by the synchrotron ring control system. The progress of computer networking systems and the technology of security control require the development of a highly flexible control system. An interlock system that is independent of the control system has increased the reliability. For the beamline control system the so-called standard model concept has been adopted. VME-bus (VME) is used as the front-end control system and a UNIX workstation as the operator console. CPU boards of the VME-bus are RISC processor-based board computers operated by a LynxOS-based HP-RT real-time operating system. The workstation and the VME are linked to each other by a network, and form the distributed system. The HP 9000/700 series with HP-UX and the HP 9000/743rt series with HP-RT are used. All the controllable apparatus may be operated from any workstation.
Calibration of space-resolving VUV and soft X-ray spectrographs for plasma diagnostics
Authors: Yoshikawa Masayuki , Yamaguchi Naohiro , Aota Tatsuya , Ikeda Katsunori , Okamoto Yuuji , Yatsu Kiyoshi , Tamano Teruo
Published: July 2004

Vacuum ultraviolet (VUV) and soft X-ray measurements are important means of diagnosing impurities in magnetically confined plasmas used in fusion research. Recently, space- and time-resolving flat-field VUV (150–1050 Å) and soft X-ray (20–350 Å) spectrographs have been constructed by using aberration-corrected concave gratings with varied-spacing grooves which give a wide simultaneous spectral coverage on a microchannel-plate intensified detector. Calibration experiments have been performed at beamlines 11A and 11C at the Photon Factory of the High Energy Accelerator Research Organization. The relative efficiency of the VUV spectrograph has been measured for P-polarization geometry in the spectrograph. In the soft X-ray spectrograph, efficiencies have been obtained for several different points of irradiation on the grating along the groove direction and for two (S and P) polarization geometries.
Mn Lα,β and F Kα resonant X-ray fluorescence spectroscopy of MnF2
Authors: Kawai Jun , Yamamoto Tokujiro , Harada Yoshihisa , Shin Shik
Published: July 2004

Mn Lα,β and F Kα1,2 (K–L
3,2) X-ray fluorescence spectra of MnF2 were measured when the excitation X-ray energy was higher and lower than the threshold energies. Monochromated synchrotron radiation was used for primary excitation. The resonance fluorescence of Mn Lβ and the multiply ionized F Kα3,4 satellites (KL–L
2) were observed.
Combined system of synchrotron radiation and laser for solid-state research
Authors: Kamada M. , Hirose S. , Asaka S. , Tsujibayashi T. , Watanabe M. , Arimoto O. , Fujiwara S. , Itoh H. , Nakanishi S. , Itoh M.
Published: July 2004

Two combined systems of synchrotron radiation and laser have been constructed for solid-state research. One is a laser-induced fluorescence system to observe synchrotron radiation-induced desorption of alkali atoms from ionic crystals, which consists of a laser diode with a high repetition rate and synchrotron radiation under a single-bunch operation. The other is a system of two-photon spectroscopy, which is based on the combination of synchrotron radiation pulses with a low intensity and high repetition rate and Nd:YAG laser pulses with a high intensity and low repetition rate. The experimental systems and the preliminary results are presented in this report.
Photoionization studies of sulfur radicals and products of their reactions
Authors: Cheng Bing-Ming , Chew Eh Piew , Hung Wen-Ching , Eberhard Jürg , Lee Yuan-Pern
Published: July 2004

A discharge flow–photoionization mass spectrometric system coupled to a synchrotron is employed to study intermediates and products of sulfur radical reactions related to atmospheric chemistry. Sulfur radicals are generated from reactions of oxygen or chlorine atoms with sulfur compounds in a flow tube. The gaseous reaction products are sampled into the ionization region via a three-stage differential pumping scheme. Photoionization spectra and ionization energies are measured by dispersing synchrotron radiation to ionize the samples. Using this technique, photoionization spectra and ionization energies of HSO, CH3SO, C2H5SO, HSCl, and some secondary reaction products, SSCl, HSSCl, HSSSH, CH3SOH and CH3SS(O)CH3, were measured for the first time.
The LNLS soft X-ray spectroscopy beamline
Authors: Tolentino H. , Compagnon-Cailhol V. , Vicentin F. C. , Abbate M.
Published: July 2004

The soft X-ray spectroscopy beamline installed at a bending-magnet source at the LNLS is described. The optics are designed to cover energies from 800 to 4000 eV with good efficiency. The focusing element is a gold-coated toroidal mirror with an angle of incidence of 17 mrad. The UHV double-crystal monochromator has three pairs of crystals, Si (111), InSb (111) and beryl (101¯0), that can be selected by a sliding movement. The UHV workstation is equipped with an ion gun, an electron gun, an electron analyser, LEED optics, an open channeltron and a photodiode array. This beamline is intended for photoemission, photoabsorption, reflectivity and dichroism experiments.
X-ray magnetic reflectometry using circularly polarized radiation
Authors: Neumann Claus , Rogalev Andrei , Goulon José , Lingham Mik , Ziegler Eric
Published: July 2004

Magnetic reflectometry experiments have been performed in the X-ray range at the L
2,3 edges of rhodium. What makes these experiments original is the insertion of a very compact double-bounce reflectometer upstream of the monochromator. This configuration makes full use of the high polarization rate of the helical undulator source. This advantage is reflected in the high quality of the data obtained after only a few accumulations. It is also shown that, by properly selecting the angle of incidence, one may obtain experimental differential X-ray reflectivity spectra dominated either by the dispersion or the absorption terms.
Soft X-ray photochemistry beamline at SPring-8
Authors: Koyano I. , Okuyama M. , Ishiguro E. , Hiraya A. , Ohashi H. , Kanashima T. , Ueda K. , Suzuki I. H. , Ibuki T.
Published: July 2004

Design and construction of a soft X-ray beamline at SPring-8 is reported. The beamline utilizes high-quality linearly polarized soft X-rays obtainable from a figure-8 undulator for the study of photophysical and photochemical processes of atoms, molecules and surfaces in the inner-shell excitation region. It consists of two experimental stations, a photochemistry station and a chemical vapour deposition (CVD) station. A high-resolution grating monochromator is installed at the photochemistry station, while the intense undispersed undulator radiation is used at the CVD station. Unique features of the experimental chambers and of the analysis and characterization systems are described along with those of the monochromator.
Absolute calibration of a soft X-ray spectrograph for X-ray laser research using white beam
Authors: Fujikawa C. , Kawachi T. , Ando K. , Yamaguchi N. , Hara T.
Published: July 2004

Absolute calibration of a soft X-ray spectrograph has been performed using a white beam of synchrotron radiation. The calibrated spectrograph was a flat-field grazing-incidence spectrograph with an X-ray CCD detector for X-ray laser research. Absolute sensitivity of the spectrograph system can be obtained from transmitted spectra using filters made of several different materials, each providing an absorption-edge wavelength standard. The absolute sensitivity determined in this work shows nearly the same behaviour with wavelength as that in another calibration experiment using a laser-produced plasma as an X-ray source.
A compact molecular-beam epitaxy apparatus for in situ soft X-ray magnetic circular dichroism experiments
Authors: Koide Tsuneharu , Shidara Tetsuo , Nakajima Nobuo , Miyauchi Hiroshi , Fukutani Hirohito
Published: July 2004

An economical and easily movable molecular-beam epitaxy (MBE) apparatus which prepares magnetic ultrathin films and superlattices with atomically well controlled interfaces has been designed and constructed. Cleaning and characterization of substrates, sample deposition in a layer-by-layer fashion, and characterization of samples both during and after growth can be carried out in a single ultrahigh vacuum (UHV) chamber. This MBE apparatus is combined with UHV high-field magneto-optical instruments for in situ soft X-ray magnetic circular dichroism experiments on two-dimensional magnetic systems.
New beamline optics for the effective use of a wiggler beam
Authors: Nakayama Kan , Okada Yosimasa , Fujimoto Hiroyuki
Published: July 2004

A hard X-ray beamline, BL13A, has been constructed for precision diffraction experiments conducted downstream of the multipole wiggler MPW#13 at the Photon Factory. The BL13A line can be used along with the main beamline, BL13B, which accepts the central 4 mrad of the 5 mrad horizontal fan. BL13A uses the remaining horizontal off-axis beam. The beam is diffracted by a double-crystal monochromator which uses asymmetric (422) diffraction with a horizontal diffraction vector. A monochromatic beam with 33.5 keV photon energy is directed to a precision goniometer. Good beam stability and high intensity were obtained.
Optical design of the U7 undulator beamline at the Pohang Light Source
Authors: Shin Hyun-Joon , Chung Y. , Kim Bongsoo
Published: July 2004

The first insertion-device beamline at the Pohang Light Source is designed for high-resolution spectroscopy and spectromicroscopy. The beamline will contain a variable-included-angle plane-grating monochromator (VIA-PGM) using a grating substrate which has seven different grooves with different depths. The advantages of this scheme will be the fixed exit-slit position and the mechanical stability of the grating scan mechanism while changing the photon energy range. The beamline is designed to cover the photon energy range 20–2000 eV. The estimated spectral resolution, E/ΔE, is above 8000 in the photon energy range below 500 eV, and above 4000 for the remaining photon energy range. The estimated flux at the end-station is of the order of 1012 photons s−1 (0.1% bandwidth)−1.
Higher-order suppression in diffraction-grating monochromators using thin films
Authors: Quinn F. M. , Teehan D. , MacDonald M. , Downes S. , Bailey P.
Published: July 2004

Although a continuously tuneable source of photons is a very desirable feature of synchrotron radiation it has one main drawback: the contamination of the photon beam by higher-order diffracted light. Several elements have absorption edges which lie between 10 and 200 eV, a range prone to high second- and third-order content in XUV monochromators. They can, therefore, be used as transmission filters to reduce this higher-order content. This paper describes the use of thin filters to reduce the higher-order content in diffraction-grating monochromators. Their suppression efficiency, transmission and ageing have been characterized using photoelectron spectroscopy and compared with calculated values. The effect of oxide contamination on their performance has been assessed. Filters are now installed on eight XUV beamlines and have been in routine use for several years.
A compact vacuum-ultraviolet beamline for synchrotron radiation photoelectron spectroscopy combined with an ion-scattering spectrometer, SORIS
Authors: Namba Hidetoshi , Obara Makoto , Kawakami Daisuke , Nishimura Tomoaki , Yan Yonglian , Yagishita Akira , Kido Yoshiaki
Published: July 2004

Apparatus for high-resolution synchrotron radiation photoelectron spectroscopy combined with high-resolution medium-energy ion scattering, named `SORIS', has been developed for simultaneous investigations of electronic states and atomic structures on surfaces. For this purpose, a compact vacuum-ultraviolet beamline of photon energy from 5 to 700 eV has been designed for the small storage ring `Aurora' installed at Ritsumeikan University. Owing to the small electron-beam size in the storage ring, an energy resolution E/dE of >5000 can be obtained.
Design of a high-flux and high-resolution VUV bending-magnet beamline
Authors: Hsieh T.-F. , Huang L.-R. , Chung S.-C. , Dann T.-E. , Tseng P.-C. , Chen C. T. , Tsang K.-L.
Published: July 2004

A high-flux and high-resolution VUV beamline (4–40 eV) has been designed and is under construction at SRRC. This beamline, which collects 50 mrad of horizontal radiation, uses a 6 m cylindrical-grating monochromator with an incident angle of 70° instead of the conventional normal-incidence-monochromator (NIM) design. Special features, such as movable entrance slit, bendable vertical focusing mirror and movable curved exit slit, are employed to enhance greatly the beamline performance. With both slit openings set at 10 µm, the energy-resolving power can reach as high as 70000. Photon fluxes of 1 × 1013 and 1 × 1010 photons s−1 are calculated for energy-resolving powers of 1000 and 40000, respectively. The best image size at the sample position is smaller than 0.45 × 0.2 mm.
Allowable aperture size of the front end for the high-heat-load undulator beamlines of SPring-8
Authors: Oura M. , Sakae H. , Sakurai Y. , Kitamura H.
Published: July 2004

A systematic study to determinine the allowable aperture size of the front end for the SPring-8 high-heat-load undulator beamlines has been performed, from the viewpoint of protecting the front-end Be window from thermomechanical failure, and based on the results of ANSYS finite-element analyses. These results have revealed that the allowable aperture size of the front end ranges approximately from 1.06 mm2 to 3.2 mm2 depending on the K-parameter and the filter thickness.
Bronchography test studies at the angiography station of the VEPP-3 storage ring
Authors: Kondratyev V. I. , Kulipanov G. N. , Kuzin M. V. , Mezentsev N. A. , Nesterov S. I. , Pinduyrin V. F.
Published: July 2004

The K-edge dichromography method was applied for preliminary bronchography test studies at the angiography station on the VEPP-3 storage ring. Images of xenon distribution over the test sample of Plexiglass were acquired. The obtained results demonstrate that thicknesses of xenon as small as 0.5 mm can be visualized.
Multiple-wavelength powder diffraction using imaging plates at the Australian National Beamline
Authors: Cookson David J. , Hunter Brett A. , Kennedy Shane J. , Garrett Richard F.
Published: July 2004

The Australian powder diffractometer at the Photon Factory is capable of recording multiple powder-diffraction scans in less than 5 min per pattern using imaging plates in Debye–Scherrer geometry. This, coupled with incrementing the X-ray beam energy in suitably small steps (down to ∼2 eV) between exposures, allows fast collection of anomalous diffraction data. Data collected from a copper oxide-based superconductor at energies near the Cu K-absorption edge are presented, along with an account of the technique used to extract multiple-exposure powder-diffraction data from imaging plates.
Site specification on normal and magnetic XANES of ferrimagnetic Fe3O4 by means of resonant magnetic Bragg scattering
Authors: Kobayashi Kenji , Kawata Hiroshi , Mori Koichi
Published: July 2004

Resonant magnetic Bragg scattering (RMBS) for several reflections has been measured at the Fe K-edge in Fe3O4. The normal and magnetic X-ray absorption near-edge structure (XANES) for two types of Fe ion site (tetrahedral and octahedral) were successfully determined from the analysis of DAFS and RMBS spectra on the assumption that there was an electric dipole transition. The obtained normal XANES for the octahedral site is well explained as a mixture of Fe2+ and Fe3+ ions, and the characteristic feature of the magnetic XANES at the pre-edge peak is mainly contributed from the Fe3+ ion at the tetrahedral site.
A grazing-incidence reflectometer for BL-39XU at SPring-8
Authors: Sakurai Kenji , Uehara Shouji , Goto Shunji
Published: July 2004

A new grazing-incidence reflectometer has been designed for the X-ray undulator beamline BL-39XU at SPring-8. It will be used for analytical applications, especially ultra-trace-level determination by total reflection X-ray fluorescence (TXRF), nanometer-scale surface topography by specular/non-specular X-ray reflection, and thin-film interface studies by combined measurements of X-ray fluorescence and X-ray reflection. The requirements for the instrument and the solutions in the present design are discussed. A prototype has been developed to test the feasibility of the design. It has been confirmed that the measurements planned at the beamline are achievable with this reflectometer.
Ti/Al multilayer zone plate and Bragg–Fresnel lens
Authors: Koike M. , Suzuki I. H. , Komiya S. , Amemiya Y.
Published: July 2004

By using a helicon plasma sputtering technique, a one-dimensional Ti/Al multilayer zone plate with an outermost layer width of 76 nm has been successfully fabricated. A Bragg–Fresnel lens has been made by combining this zone plate with a Ge(422) crystal. Comparison of the Ti/Al multilayer zone plate with the Ag/Al zone plate is discussed in terms of focusing efficiency.
Trace element analysis on Si wafer surfaces by TXRF at the ID32 ESRF undulator beamline
Authors: Ortega Luc , Comin Fabio , Formoso Vincenzo , Stierle Andreas
Published: July 2004

Synchrotron radiation total-reflection X-ray fluorescence (SR-TXRF) has been applied to the impurity analysis of Si wafers using a third-generation synchrotron radiation undulator source. A lower limit of detectability (LLD) for Ni atoms of 17 fg (1.7 × 108 atoms cm−2) has been achieved with an optical set-up based on an Si(111) double-crystal monochromator and a horizontal sample geometry. These first results are very promising for synchrotron radiation trace element analysis since we estimate that it is possible to lower the LLD by a factor of about 25 by employing appropriate optics and detectors. The use of a crystal monochromator opens new possibilities to perform absorption and scattering experiments (NEXAFS and X-ray standing-wave methods) for chemical and structural analysis of ultratrace elements.
XAFS in the high-energy region
Authors: Nishihata Y. , Kamishima O. , Kubozono Y. , Maeda H. , Emura S.
Published: July 2004

XAFS (X-ray absorption fine-structure) spectra were measured near K-absorption edges of Ce (40.5 keV), Dy (53.8 keV), Ta (67.4 keV) and Pt (78.4 keV). The blunt K-edge jump due to the finite lifetime of the core hole was observed. This makes it difficult to extract EXAFS (extended X-ray absorption fine-structure) functions at low k values. Local structure parameters can be evaluated from the EXAFS spectra above K-absorption edges in the high-energy region as well as from those above L
III-edges. It was found that the finite-lifetime effect of the core hole is effectively taken into the photoelectron mean-free-path term, as predicted theoretically.
Structural studies of endohedral metallofullerenes by synchrotron radiation powder diffraction
Authors: Nishibori E. , Takata M. , Sakata M. , Shinohara H.
Published: July 2004

The endohedral natures of the metallofullerenes Y@C82 and Sc2@C84 are described based on synchrotron radiation powder diffraction experiments. For structural analysis, a combination of the maximum-entropy method (MEM) and Rietveld refinement was employed to analyse the complicated powder pattern. The obtained MEM charge densities show a clear distinction of the endohedral natures of the mono- and dimetallofullerenes.
Partial structural functions of binary liquids estimated from anomalous X-ray scattering measurements
Authors: Waseda Yoshio , Saito Masatoshi , Park Changyong , Omote Kazuhiko
Published: July 2004

A new apparatus has been built for structural studies of high-temperature liquids using the anomalous X-ray scattering (AXS) method with synchrotron radiation. AXS measurements were made in the asymmetrical reflection mode for a free liquid surface by changing the beam direction using an additional mirror system. The usefulness and capabilities of this new equipment were confirmed by obtaining the individual partial structural functions of liquid Bi30Ga70 alloy.
Angle-resolved UV photoelectron spectra (UPS) of thin films of perylene-3,4,9,10-tetracarboxylic dianhydride on MoS2
Authors: Azuma Yasushi , Hasebe Takehiko , Miyamae Takayuki , Okudaira Koji K. , Harada Yoshiya , Seki Kazuhiko , Morikawa Eizi , Saile Volker , Ueno Nobuo
Published: July 2004

Angle-resolved UV photoelectron spectra (ARUPS) were measured for thin films of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) deposited on cleaved MoS2 surfaces. The take-off angle (θ) dependence of the photoelectron intensity of the highest π band showed a sharp maximum at θ = 32–34°. A spectral feature of the binding energy at ∼8.9 eV, which is believed to originate from a π state, showed a remarkably different θ dependence from that of the π band. A quantitative analysis of the observed θ dependencies clearly indicates that (a) the feature at ∼8.9 eV originates from the oxygen 2p non-bonding states and (b) the molecules lie flat on the substrate surface.
Temperature dependence of photoelectron angular distribution from thin films of chloroaluminum phthalocyanine on MoS2
Authors: Azuma Yasushi , Tsutsui Masahiko , Kera Satoshi , Aoki Masaru , Miyamae Takayuki , Okudaira Koji K. , Harada Yoshiya , Ueno Nobuo
Published: July 2004

Angle-resolved UV photoelectron spectra were measured for thin films of chloroaluminum phthalocyanine deposited on cleaved MoS2 surfaces. The take-off angle (θ) dependence of the photoelectron intensity of the highest π band showed a remarkable sharpening upon cooling the film, indicating that thermal excitation of molecular vibrations gives a considerable broadening of the photoelectron angular distribution. The θ dependence observed at ∼120 K agrees well with that calculated.
Smart X-ray beam position monitor system using artificial-intelligence methods for the Advanced Photon Source insertion-device beamlines
Authors: Shu Deming , Ding Hai , Barraza Juan , Kuzay Tuncer M. , Haeffner Dean , Ramanathan Mohan
Published: July 2004

At the Advanced Photon Source (APS), each insertion-device (ID) beamline front end has two X-ray beam position monitors (XBPMs) to monitor the X-ray beam position for both vertical and horizontal directions. Performance challenges for a conventional photoemission-type XBPM during operations are contamination of the signal from the neighbouring bending-magnet sources and the sensitivity of the XBPM to the insertion-device gap variations. Problems are exacerbated because users change the ID gap during their operations, and hence the percentage level of the contamination in the front-end XBPM signals varies. A smart XBPM system with a high-speed digital signal processor has been built at the Advanced Photon Source for the ID beamline front ends. The new version of the software, which uses an artificial-intelligence method, provides a self-learning and self-calibration capability to the smart XBPM system. The structure of and recent test results with the system are presented in this paper.
Diagnostic front end for BESSY II
Authors: Peatman W. B. , Holldack K.
Published: July 2004

For BESSY II, synchrotron radiation beam diagnostics will be incorporated in both the insertion-device front ends and the dipole-beamline front ends. In order to gain a complete picture of the source characteristics, a diagnostic front end has been designed and tested for dipole radiation. This consists of (i) a pinhole array imaging system, (ii) a double-blade system for the determination of the vertical center of gravity of the synchrotron radiation fan, and (iii) a Bragg–Fresnel multilayer system for the most precise image information about the source size and shape.
Spectral properties of the polarizing devices at SRRC
Authors: Wang Ch. , Chang L. H. , Lin M. C. , Chen J.-R.
Published: July 2004

User requirements at SRRC for high-brilliance synchrotron light in various polarization states will be fulfilled in the near future by the implementation of two types of polarizing devices in the storage ring: the elliptically polarizing undulator (EPU) and the elliptically polarized bending magnet (EPBM). The EPBM provides a broadband polarized spectrum up to the soft X-ray range with rapid alternation of the left and right helicities. The EPU, which has a magnetic period length of 56 mm, generates a high-brilliance harmonic spectral intensity in the range 80–1400 eV with abundant polarization states, including circular ones. The optimal merit flux is evaluated for the operation of these two polarizing devices in the SRRC 1.5 GeV storage ring. The available polarization states are also surveyed.
Development of an elliptical multipole wiggler at SPring-8
Authors: Maréchal Xavier-Marie , Hara Toru , Tanabe Toshiya , Tanaka Takashi , Kitamura Hideo
Published: July 2004

An elliptical multipole wiggler (EMPW) based on a new concept has been installed on the SPring-8 storage ring. The EMPW, with a 120 mm period, has a critical energy of 50 keV at a gap of 20 mm. It will provide high-brilliance hard circularly polarized X-rays in the 100–300 keV range to the pilot beamline dedicated to materials science: the Compton scattering beamline. Field measurements, field integrals, the expected fluxes, polarization rates, power and power densities are presented for two operating gaps: 30 mm during commissioning, 20 mm later.
Performance of a fixed-taper in-vacuum undulator at SPring-8
Authors: Maréchal Xavier-Marie
Published: July 2004

With an in-vacuum undulator, the smallest gaps can be used to achieve high-brilliance radiation within a small spectral width around the harmonics of the fundamental. However, some experiments require a scan over a much wider range of energy within timescales which are impossible to reach via gap tuning. For standard undulators a flat spectrum is usually obtained by using a variable tapered gap. Unfortunately, the mechanical design of the in-vacuum undulator used at SPring-8 is hardly compatible with the extra degree of freedom necessary to adjust the taper mechanically. New magnetic designs are investigated to overcome this problem; their performances are compared with the performances of a fixed-taper in-vacuum undulator for a source of photons in the 5–15 keV range (energy of the fundamental) with an energy width of 1.5 keV.
Design of an 18 m spherical-grating monochromator at UVSOR
Authors: Yoshida Hiroaki , Mitsuke Koichiro
Published: July 2004

An 18 m spherical-grating monochromator with high resolution and high photon flux has been developed at the bending-magnet beamline BL2B2 of the UVSOR facility in the Institute for Molecular Science. The monochromator is designed to cover the energy range 20–200 eV by using three gratings: G1 (2400 lines mm−1, R = 18 m) at 80–200 eV; G2 (1200 lines mm−1, R = 18 m) at 40–100 eV; G3 (2400 lines mm−1, R = 9.25 m) at 20–50 eV. A resolving power of 5000 and a photon flux of more than 1010 photons s−1 are expected at a 100 mA ring current. A small including angle of 140° is adopted for G3 and two plane mirrors coated with aluminium are located between G3 and the exit slit as optical filters. These geometrical devices may contribute significantly to the reduction of the high-order lights.
Microcontroller-based servo for two-crystal X-ray monochromators
Authors: Siddons D. P.
Published: July 2004

Microcontrollers have become increasingly easy to incorporate into instruments as the architectures and support tools have developed. The PIC series is particularly easy to use, and this paper describes a controller used to stabilize the output of a two-crystal X-ray monochromator at a given offset from its peak intensity position, as such monochromators are generally used.
Optical design for a bending-magnet beamline based on a varied-line-spacing plane grating
Authors: Kiyokura Takanori , Maeda Fumihiko , Watanabe Yoshio
Published: July 2004

A vacuum ultraviolet beamline with a grazing-incidence constant-deviation-angle monochromator, equipped with a varied-line-spacing plane grating, has been designed for a bending-magnet light source. This type of monochromator has become very popular because of its high resolution, high throughput, simple scanning mechanism and fixed exit slit. To improve the energy resolution for a wide spectral range, Yan & Yagishita [(1995), KEK Report 95-9. KEK, Tsukuba, Ibaraki 305, Japan] proposed eliminating the defocus aberration at two specific energies in the spectral range, and their monochromator successfully achieved higher energy resolution by using an undulator light source. The possibility of applying this method to a bending-magnet beamline was examined and it was found that high performance can be achieved even using a bending-magnet light source with wide emittance. Performance evaluation relating to energy resolution, photon flux and spot size are reported.
A high-performance double-crystal monochromator soft X-ray beamline
Authors: Dann Tang-Eh , Chung Shih-Chun , Huang Liang-Jen , Juang Jwei-Ming , Chen Ching-Iue , Tsang King-Long
Published: July 2004

A high-performance double-crystal-monochromator soft X-ray (DCMSX) beamline has been constructed at the Synchrotron Radiation Research Center (SRRC). This beamline delivers monochromatic photon beams with energies from 1 to 9 keV and a resolving power (E/ΔE) of up to 7000. This beamline provides users with an opportunity to study many important materials, such as high-Tc
superconductors, magnetic materials, catalysts, super-alloy compounds etc. Excellent EXAFS and NEXFS spectra have been routinely obtained from this beamline. Several interesting research projects are currently being conducted at this beamline. All the results show that this beamline has been constructed to meet its design goals.
High-flux and high-resolution spectroscopic facility in the VUV region at Super-ACO
Authors: Ito K. , Lagarde B. , Polack F. , Alcaraz C. , Nahon L.
Published: July 2004

A new spectroscopic facility, consisting of a planar/helical undulator and a 6.65 m off-plane Eagle monochromator, has been designed. It can supply high-flux and high-resolution photons with `exotic' polarization in the 5–40 eV energy range. The astigmatism can be compromised by horizontally focusing the incident radiation on the grating. The rotation of a post-focusing toroidal mirror compensates for the deviation of the exit beam caused by the grating translation. The whole system will be installed at beamline SU5 of SUPER-ACO (0.8 GeV) at the beginning of 1998. With a 4300 grooves mm−1 grating, a resolving power of around 105 is expected at 20 eV.
Performance of the YB66 soft X-ray monochromator crystal at the wiggler beamline of the UVSOR facility
Authors: Kinoshita Toyohiko , Takata Yasutaka , Matsukawa Tokuo , Aritani Hirofumi , Matsuo Shigehiro , Yamamoto Takashi , Takahashi Masao , Yoshida Hisao , Yoshida Tomoko , Ufuktepe Yüksel , Nath Krishna G. , Kimura Shin-ichi , Kitajima Yoshinori
Published: July 2004

Soft X-ray spectra have been measured using a pair of YB66(400) monochromator crystals at the double-crystal monochromator beamline BL7A of the UVSOR facility, where the wiggler radiation has a magnetic field of 4 T. Deformation of the YB66 crystal due to heat load from the synchrotron radiation is almost negligible. The photon flux is about 108 photons s−1 (100 mA)−1 in the energy region 1.2–2 keV and the energy resolution is 0.7 ± 0.1 eV around hν = 1.5 keV. These results show that the YB66 crystal is suitable for use as a monochromator crystal. Its application to soft X-ray spectroscopy is discussed.
The white-radiation dynamic topography experimental system at the BSRF
Authors: Wang G. L. , Jiang J. H. , Tian Y. L. , Han Y. , Wang Z. G.
Published: July 2004

A white-radiation dynamic topography experimental system has been established at the BSRF (Beijing Synchrotron Radiation Facility) and is now in operation. Each part of this system is described in this paper, with particular emphasis given to the PC-based online control system, the X-ray video-imaging system and the image-treatment system. Moreover, some of the experimental results, such as the phase transition of KNbO3 nonlinear optical crystals and of blue bronze charge-density-wave material, are briefly presented.
A bent Laue analyser crystal for Rayleigh-to-Compton computed tomography
Authors: Schulze Clemens , Kleuker Ulf
Published: July 2004

A new optical system to perform tomography based on the Rayleigh-to-Compton (RC) method with high spatial and spectral resolution is presented. The RC technique allows the effective atomic number of a sample to be measured and finds application in bone mineral densitometry in medicine. It is particularly useful for the characterization of the distribution of biological materials which do not exhibit distinctive diffraction peaks. The system is based on the separation of the elastic line from the spectrum that is scattered by the sample by means of a bent Laue analyser crystal, and the subsequent independent detection of the elastic and inelastic parts of the spectrum with two large-area scintillation counters. The high energy resolution permits operation at low momentum transfer, where the RC method has its best contrast-to-noise ratio for low-Z materials. The geometrical and spectral requirements in terms of the incident beam and the conical analyser crystal are discussed. A first-generation tomographic imaging system (pencil beam, scanned sample) as implemented at the ESRF Compton-Scattering Station ID15B is described. A high-resolution tomographic reconstruction of a bone sample is presented.
Application of a Varied-Line-Spacing Grating in a High-Performance Soft X-ray Monochromator
Authors: Yan Yonglian , Shigemasa Eiji , Yagishita Akira
Published: July 2004

The design and experimental evaluation of a high-resolution varied-line-spacing-grating monochromator constructed at the Photon Factory are described. Various applications of a varied-line-spacing grating in a high-performance soft X-ray monochromator are discussed.
Protein crystallography using a multilayer monochromator
Authors: Deacon Ashley M. , Appleby Todd , Bilderback Donald H. , Ealick Steven E. , Fontes Ernest , Thiel Daniel J.
Published: July 2004

A multilayer monochromator was installed on a bending-magnet beamline at the Cornell High Energy Synchrotron Source (CHESS) and was used to provide an unfocused pseudo-monochromatic X-ray beam for protein crystallography experiments. Datasets were collected from lysozyme at room temperature and human methylthioadenosine phosphorylase at 100 K. The wide energy bandpass of the multilayer allowed short exposure times, typically only a few times longer than on a focused multipole wiggler beamline. The diffraction images were processed using unmodified monochromatic data-processing software to yield datasets of good quality. These first measurements demonstrate that multilayer monochromators can be readily applied to the rapid structure determination of many typical-sized macromolecules.
Focusing monochromator and imaging-plate camera for grazing-incidence diffraction studies of thin films
Authors: Foran Garry J. , Garrett Richard F. , Gentle Ian R. , Creagh Dudley C. , Peng Jian Bang , Barnes Geoffrey T.
Published: July 2004

A multiple-imaging-plate detector system and focusing monochromator have been developed and successfully applied to the time-resolved study of phase transitions in Langmuir–Blodgett films by grazing-incidence X-ray diffraction (GIXD). The monochromator described here combines fixed-exit-beam height with sagittal focusing of the second crystal. The design is similar to that of Matsushita et al. [Matsushita, Ishikawa & Oyanagi (1986). Nucl. Instrum. Methods, A246, 377–379], with the exception that the motion of the first crystal is achieved via a computer-controlled X-Y translation table rather than a set of cams. The second crystal is a ribbed Si(111) wafer mounted in a four-point bending mechanism. The first reported application of imaging plates to a GIXD study was carried out by our group and proved to be very successful in the determination of thin-film structure [Foran, Peng, Steitz, Barnes & Gentle (1996). Langmuir, 12, 774–777]. To extend the capabilities of this system, an imaging-plate camera was designed and built which can accommodate up to 13 imaging plates (40 × 20 cm) inside the vacuum chamber of the main diffractometer at the Australian Beamline at the Photon Factory.
Layered structure analysis of GMR multilayers by X-ray reflectometry using the anomalous dispersion effect
Authors: Hirano Tatsumi , Usami Katsuhisa , Ueda Kazuhiro , Hoshiya Hiroyuki
Published: July 2004

As a basic layered structure for giant magnetoresistive (GMR) heads, NiFe/Cu/NiFe/Ta/Si substrate was measured by X-ray reflectometry at Cu Kα, Cu Kβ and Cu K-absorption-edge energies. The accuracy of both the Cu thickness and the interface width between the upper NiFe and the Cu layers was found to improve in the order Cu Kα < Cu Kβ < Cu K-edge. The final thickness and interface width values obtained from Cu Kβ reflectivity are in good agreement with those from the Cu K-edge. The anomalous-dispersion effect is useful in the more accurate analysis of the layered structure of transition metal multilayers because it causes a large difference in the refractive indices of specific elements near the absorption edge. The Kβ X-rays, which can be produced from conventional X-ray sources, are also available for the accurate analysis of reflectivity measurements.
Development of an in-situ X-ray diffraction system for observation of electrodeposition of metallic layers
Authors: Imafuku Muneyuki , Kurosaki Masao , Kawasaki Koichi
Published: July 2004

In order to study the dynamic phenomena of electrodeposition of metallic layers, an in situ X-ray diffraction system has been newly developed using an electrochemical cell and an image-plate detector. Electrodeposition of Zn on an Fe(100) single-crystal surface with a current density at 0.5 A cm−2 was demonstrated in this study. Time-resolved diffraction patterns were obtained by scanning the image plate. It was found that Zn(101) layers were mainly formed from the initial stage of deposition and grew continuously on this substrate. Growth of other layers, such as Zn(103), Zn(110) and Zn(102), were also detected. On the other hand, Zn(100) and Zn(002) were not observed under this condition.
Source, optical and detector requirements for X-ray diffraction and scattering
Authors: Nave Colin
Published: July 2004

The standard curves used to describe the properties of synchrotron radiation sources usually consist of a plot of the flux or brightness from the source as a function of wavelength. These curves are useful for the case where a high flux or brightness is required. Many experiments do not fall into this category. An alternative description of the source requirements is to provide the maximum flux into the phase space volume defined by the specimen. A diagrammatic way of illustrating how this can be achieved is derived. This illustrates how the source, optics and detectors can be matched to the requirements of a particular experiment. This approach is illustrated using, as examples, a beamline on the SRS and two beamlines planned for DIAMOND, the proposed new UK third-generation source.
Electronics for SPring-8 X-ray beam monitors
Authors: Kudo Togo , Aoyagi Hideki , Shiwaku Hideaki , Sakurai Yoshiharu , Kitamura Hideo
Published: July 2004

A sensitive current-measuring system is required to construct a highly sensitive X-ray beam-position monitor (XBPM). A current–voltage converter (I/V) which can measure currents between 0.1 nA and 10 mA was designed, and the signal processing system of the XBPM was constucted using this I/V. This system was used in beamline commissioning. Beam-position data standard deviations of σ ≃ 3 µm for the bending-magnet beamline, and σ
x
≃ 3 µm and σ
y
≃ 1 µm for the insertion-device beamline were obtained during the beamline commissioning.
New methods for semiconductor charge-diffusion-length measurements using synchrotron radiation
Authors: Kohagura J. , Cho T. , Hirata M. , Okamura T. , Tamano T. , Yatsu K. , Miyoshi S. , Hirano K. , Maezawa H.
Published: July 2004

The extension of a new theory on the X-ray energy response of semiconductor detectors is carried out to characterize the X-ray response of a multichannel semiconductor detector fabricated on one silicon wafer. Recently, these multichannel detectors have been widely utilized for position-sensitive observations in various research fields, including synchrotron radiation research and fusion-plasma investigations. This article represents the verification of the physics essentials of a proposed theory on the X-ray response of semiconductor detectors. The three-dimensional charge-diffusion effects on the adjoining detector-channel signals are experimentally demonstrated at the Photon Factory for two types of multichannel detectors. These findings are conveniently applicable for measuring diffusion lengths for industrial requirements.
Design of beamline optics for EUVL
Authors: Watanabe Takeo , Haga Tsuneyuki , Niibe Masahito , Kinoshita Hiroo
Published: July 2004

The design of front-end collimating optics for extreme-ultraviolet lithography (EUVL) is reported. For EUVL, collimating optics consisting of a concave toroidal mirror and a convex toroidal mirror can achieve shorter optical path lengths than collimating optics consisting of two concave toroidal mirrors. Collimating optics consisting of a concave toroidal mirror and a convex toroidal mirror are discussed. The design of collimating optics for EUVL beamlines based on ray-tracing studies is described.
Absolute soft X-ray measurements using an ion chamber
Authors: Saito Norio , Suzuki Isao H.
Published: July 2004

Measurements of soft X-ray absolute intensities have been carried out using a double ion chamber and monochromated synchrotron radiation. The chamber is cylindrical and 1.3 m long. The soft X-ray beam enters the chamber at a position off the central axis, and the produced ions are collected with electrodes on the opposite side to the photon entrance. An index constant for rare gas, the γ-value, which is the average number of electrons emitted from an atom having absorbed a photon, was used for obtaining the absolute photon intensity. The obtained intensity ranges from 1 Gphotons s−1 to 25 Gphotons s−1 in the energy range 72–800 eV. The estimated uncertainty is about 5–20% depending on the intensity and the spectral purity of the soft X-rays.
Micro X-ray diffraction analysis of thin films using grazing-exit conditions
Authors: Noma Takashi , Iida Atsuo
Published: July 2004

An X-ray diffraction technique using a hard X-ray microbeam for thin-film analysis has been developed. To optimize the spatial resolution and the surface sensitivity, the X-ray microbeam strikes the sample surface at a large glancing angle while the diffracted X-ray signal is detected with a small (grazing) exit angle. Kirkpatrick–Baez optics developed at the Photon Factory were used, in combination with a multilayer monochromator, for focusing X-rays. The focused beam size was about 10 × 10 µm. X-ray diffraction patterns of Pd, Pt and their layered structure were measured. Using a small exit angle, the signal-to-background ratio was improved due to a shallow escape depth. Under the grazing-exit condition, the refraction effect of diffracted X-rays was observed, indicating the possibility of surface sensitivity.