The Advanced Light Source (ALS) now under construction at the Lawrence Berkeley Laboratory will be a national user facility for the production ofhigh-brightness and partially coherent soft x-ray and ultraviolet synchrotron radiation. The ALS is based on a low-emittance electron storage ring optimized for operation at 1. 5 GeV with insertion devices in 10 long straight sections and 24 premier bend-magnet ports. High-brightness photon beams from less than 10 eV to more than 2 keY will be produced by undulators thereby providing many research opportunities in materials and surface science biology atomic physics and chemistry. Wigglers and bend magnets will provide high-flux broad-band radiation at energies to 10 keY. 2.

The Advanced Photon Source at Argonne National Laboratory has been designed as a national user facility for synchrotron-radiation researchers from industry universities and national laboratories. By providing x-ray beams more brilliant than those currently available the APS promises to play a substantial role in any discipline where knowledge of the structure of matter is important from basic research in materials and chemistry to condensed-matter physics biology and medical applications. The science now in progress at existing synchrotron-radiation facilities and the science being proposed for the APS underlie virtually all modem technologies.

Japan Atomic Energy research Institute(JAERI) and the Institute of Physical and Chemical Research (RIKEN) are going to build an 8GeV synchrotron radiation source in Harima Science Garden City of Hyougo Prefecture. The facility consists of a 8 GeV storage ring of 1436 circumference with a natural emiuance of 7. 2 nmrad. an injector linac of 1 GeV and a 8 GeV synchrotron. Construction starts in 1990 and the first stored beam is foreseen in 1998. At the commissioning time 10 beam lines will be available while the remaining 50 beam lines 32 on insertion devices and 18 on bending magnets will be constructed successively. All these beam lines will be used by external groups.

Insertion device (ID) synchrotron x-ray sources on present day and next-generation synchrotron facilities have very attractive spectral properties. In addition however they are capable of producing x-ray beams with large powers and in some cases unprecedented power densities. An overview of the spatial and frequency distributions of these sources including the effects of synchrotron particle beam emittance is presented. 1.

Abstract not available.

The powerful beams of x-ray radiation generated by insertion devices at high power synchrotron facilities deposit substantial amounts of localized heat in the front end and optical components that they intercept. X-ray beams from undulator sources in particular are confined to very narrow solid angles and therefore impose very high absorbed heat fluxes. This paper is devoted to a detailed study of the design of windows for the Advanced Photon Source undulators and wigglers emphasizing alternative design concepts material considerations and cooling techniques necessary for handling the high heat load of the insertion devices. Various designs are thermally and structurally analyzed by numerically simulating full-power operating conditions. This analysis also has relevance to the design and development of other beam line components which are subjected to the high heat loads of insertion devices. Key indices: synchrotron radiation high heat load insertion devices undulators wigglers beryllium window. 2.

The Advanced Photon Source (APS) to be constructed at Argonne National Laboratory (ANL) utilizes magnetic devices which generate X-ray beams with very intense heat flux levels. The Fixed Mask Assembly (FMA) is the first component to interact with the X-ray beam. Two sets of a pair of FMA channels vertically and horizontally disposed contain the beam rather than define it. They are subject to very large heat fluxes during containment. In current practice the FMA channels are made of heavy seamless copper have rectangular cross-sections and are cooled internally with water. Channels are set at grazing angles ranging from 1 to 6 degrees with respect to the beam depending on the type of insertion device. APS insertion devices will impose higher heat fluxes on FMAs. Therefore a need exists to improve the FMA engineering keeping in mind the current design criteria and philosophy of FMAs. A comparative investigation of the conventionally achievable heat transfer coefficient h" with water and the wall conductance of a heavy wall copper tube reveals that major resistance is on the coolant side. Therefore there exists a significant opportunity to improve heat transfer in the tubes by enhancement of the coolant side. To this end an experimentally and analytically based research program has been adopted at the APS for investigating enhanced cooling methods and techniques. Currently a variety of copper wool filled tubes as well as a

A compact Penning discharge VUV and soft x-ray source has been developed. It consists of a water cooled brass anode two changeable cathode inserts and two permanent magnets to produce the necessary homogeneous magnetic field along the direction of discharge axis. Argon nitrogen and helium are used as working gases with the dynamic pressure centered at 5. 0 x103 Torr. Experiments of using different cathode inserts were carried out for determining the suitable cathodegas pair. The source can produce a great nurnbr of bright lines in the VUV and soft x-ray region from 50 to 1000 A. The most useful lines are however the highly ionized aluminum and magnesium (cathode inserts material) lines below 300 A. This source has been intensively employed in our research programs and the stability shown in these applications is better than 5 within an hour. 1.

10 kW and 2kw wall stabilized argon arc sources have been developed in this institute as VUV spectroradiometric standard sources. The stability and reproducibility are better than 0. 2. Plasma spectroscopic diagnostics shows that the plasma temperature is 12759 K and the electron density is 1. 36x1023 m3 when the arc current is 40 A and argon pressure is 1. 75x10S'' Pa. Richter method absolute method relative method and computer spectral line reconstruction technique were used for plasma diagnostics. Based on McPherson 2253 M5 normal incidence VUV monochromator a computer controlled VUV spectroradiometer was set up. Impurity gases such as N1COKr Owere put into 10 kW arc and several black body limited lines (BBLL) were produced from 100 to 250 nm. These lines were used to calibrate deuterium lamp as transfer standard. 1.

Techniques for time-resolved X-ray scattering on time scales varying from kiloseconds to picoseconds are reviewed. It is concluded that the pulsed time structure and the high photon fluxes available from synchrotron X-ray sources provide new opportunities for time-resolved X-ray scattering investigations. Synchrotron beams typically consist of subnanosecond pulses of X-rays separated in time by a few tens of nanoseconds to a few hundred nanoseconds so that these beams appear as continuous X-ray sources for investigations of phenomena on time scales ranging from hours down to microseconds. Studies requiring time-resolution in the microsecond range can be carried out in a triggering mode by stimulating the phenomenon under consideration in coincidence with the X-ray pulses. Time resolution on the picosecond scale can be achieved through streak camera techniques in which the time structure of the individual X-ray pulses are viewed as quasi-continuous sources with about 100-200 picoseconds duration.

The advent of extremely bright x-ray beams from new low-emittance sources such as ESRF and APS offers new opportunities for materials research. One of the most exciting and technologically demanding areas is likely to be time-resolved x-ray studies. Our recent experiments at NSLS Brookhaven (Beamline X-16B) explore some of the challenges for time-resolved x-ray scattering combining developments in x-ray optics (dispersive geometry) area detectors (CCD''s) and fast data acquisition. The techniques are illustrated with results on the rapid thermal annealing of electronic materials including strained-layer InGai_As quantum-well structures. We describe the application of a new virtual-phase CCD detector for real-time diffraction studies at the microsecond time scale. 1.

We review the properties and operating principles of the new types of synchrotron radiation devices that produce circular polarization or polarization that can be modulated in arbitrary fashion. 1.

The use of the unique polarization properties of synchrotron radiation in the hard x-ray spectral region (E KeY) is becoming increasingly important to many synchrotron radiation researchers. The radiation emitted from bending magnets and conventional (planar) insertion devices (IDs) is highly linearly polarized in the plane of the particle''s orbit. Elliptically polarized x-rays can also be obtained by going offaxis on a bending magnet source albeit with considerable loss of flux. The polarization properties of synchrotron radiation can be further tailored to the researcher''s specific needs through the use of specialized insertion devices such as helical and crossed undulators and asymmetrical wigglers. Even with the possibility of producing a specific polarization there is still the need to develop x-ray optical components which can manipulate the polarization for both analysis and further modification of the polarization state. A survey of techniques for producing and analyzing both linear and circular polarized xrays will be presented with emphasis on those techniques which rely on single crystal optical components. 1.

X-ray absorption spectroscopy based on the polarized nature of synchrotron radiation is considered. It is concluded that linearly polarized radiation can be used for studying the anisotropic nature of electronic and atomic structure by measuring X-ray absorption near edge structure and extended X-ray absorption fine structure spectra of single crystals or oriented powders. Circularly polarized radiation can be used for studying the spin density of final electronic states in a magnetic system. Particular attention is given to experimental results on absorption of linearly polarized radiation through a highly anisotropic medium of oriented copper oxides at the Cu K-edge.

Spatial resolution and focusing efficiency are two important properties of a zone plate in x-ray focusing applications. A general expression of the zone plate equation describing its zone registration is derived from the interference of spherical waves emited from two mutually coherent point sources. An analytical expression of the focusing efficiency in terms of the zone plate thickness and x-ray refractive indices of the zones is also derived. Validity condition for using this expression is considered. Thickness required for obtaining adequate focusing efficiency is calculated as a function of x-ray energy for several representative materials. The spatial resolution of a finite thickness zone plate is worse than that of an infinetly thin zone plate which is approximately equal to the smallest zone width of the zone plate. The effect of the finite thickness on the spatial resolution is considered. This manuscript has been authored under contract number W-31-109-ENG-38 with the U. S. Department of Energy. Accordingly the U. S. Government retains a non-exclusive royalty-free license to publish or reproduce the published form of this contribution or allow others todo so for U. S. Government purposes. 146 / SPIE Vol 1345 Advanced X-Ray/EUV Radiation Sources andApplications(1990)

Tungsten, iron, and rhodium materials have been deposited alternatively with carbon and boron carbide by diode RF-sputtering. The multilayer performances have been measured at the carbon or boron K-alpha lines depending on the layer spacing. It is found that tungsten and iron provide multilayers with good optical quality and optimized layer densities. This is related to the amorphous character of the tungsten and iron layers which results in low intrinsic roughness and limited interdiffusion. The experimental reflectivity is a factor of 2/3 lower than the theoretical value for W/C multilayers at 44.7 A. Rhodium layers alternated with carbon are crystallized, which induces significant interface roughness and poor soft X-ray performances. It is concluded that boron-carbide-based multilayers always exhibit lower interface roughness than carbon-based ones.

The lateral-periodicities of the surface and interfacial roughnesses of a multilayer- Bragg reflector which affect x-ray reflectivity have been examined using the x-ray rocking curve profile measurements and a stylus surface profilometer. Multilayered films have been fabricated by a proprietary sputtering technique. The x-ray rocking curve profiles of the first Bragg reflection of the multilayered films have been examined with a precision x-ray diffractometer. These profiles show that the lateral-periodicity of the film surface and interfacial roughness which primarily affect the CuKa X-ray reflectivity is about 4 rim. The measured CuKa x-ray reflectivity of the multilayered film is in good agreement with calculations which incorporate the estimated film surface and interfacial roughness. 1.

A broadband Rh/C (50/50) multilayer coating was deposited on a blazed reflection grating replica sample. A calculation of possible materials and configurations showed that a 6-layer pair multilayer of rhodium/carbon or a 7 layer of nickel/carbon covered by 2 nm rhodium layer would give a factor of 6-10 increase in reflection efficiency depending on the roughness of the layer interfaces. Measurements with X-rays at wavelengths down to 0.4 nm on a Rh/C multilayer blazed grating combination showed a substantial increase in reflectivity with respect to a gold coated grating for a fixed angle of incidence of 1 deg.

A periodic structure alternating three different materials has been investigated and fabricated using a diode RF-sputtering system. Reflectivity was optimized using the wave propagation method. It is concluded that the amorphous character of the rhodium layers is enhanced in the W/Rh/C structures, and good reflectivities have been obtained at the carbon K-alpha line with trilayer structures including a great number of periods (28 percent of reflectivity for 40 periods stack). Some reduction of the boron interdiffusion is observed in the W/Rh/C structures, which leads to better soft X-ray performances at the boron K-alpha line (19 percent of reflectivity for a 40 periods stack).

The current works and efforts of the authors for making muLtiLayered ptane and concave mirrors in VUV and soft x-ray region are described. These incLude the principLe of seLecting coating materiaLs and optimum design the fabrication of substrates the deposition using eectron beam evaporation the test and evatuation of performance and the preparation of faciLities. 1 .

An X-ray photoelectron microscope capable of providing both spatial and chemical information on the nature of a sample has been developed. Photons from the Aladdin Synchrotron are monochromatized by an extended-range Grasshopper monochromator covering the range from 40 to 1500 eV with an energy resolution between 10 and 200 meV. The monochromatized radiation generates photoelectrons in the sample, which is energy-analyzed with a resolving power E/delta E greater than 50,000 and imaged by a multichannel plate array. The visible image is transferred to a computer by a virtual-phase charge-coupled device camera with a dynamic range of 4096:1. Preliminary coarse measurements indicate a spatial resolution of the instrument better than 1 micron, although a limit of 600 A is possible. The instrument provides chemical shift-resolved images of low-lying core levels in a variety of samples.

In this paper we discuss the potential for application of x-ray holographic imaging techniques to the sequencing of DNA. We formulate an approximate model for the scattering of partially coherent x-rays from an oriented DNA fiber and show the feasibility of reconstruction of heavy atom label positions from the x-ray scattering data. A series of simulations has been done to demonstrate the required reconstruction algorithms. An x-ray experiment is currently in progress to demonstrate the real feasibility of the technique. The potential of x-ray imaging techniques for the sequencing of DNA is attractive because of their inherently parallel nature. Hundreds or thousands of base pairs could be sequenced in a single set of x-ray images. The fundamental idea is to attach heavy atom labels to a selected base type on the DNA fragment to be sequenced. A large number 1012) of identical fragments can be constructed as an oriented fiber and illuminated with partially coherent x-rays. The heavy label positions can then be determined from the recorded pattern of scattered x-rays. If this operation is repeated for each of the four bases the sequence can be reconstructed. The phase determination problem is solved by attaching to each DNA fragment a reference label in a known position. The scattered field then forms a Fourier transform hologram of the averaged DNA fragment. Because of the high photoelectric absorption of DNA relative to its

Linearly polarized synchrotron radiation is used to study the structure of magnetically aligned layered copper oxide high temperature superconductors. Polarized extended X-ray absorption fine structure (EXAFS) measurements of oriented powders of YBa2Cu3O6.9 are reported at temperatures ranging from 20-300 K. Measurements made at the Cu K-edge with the X-ray polarization vector oriented perpendicular and parallel to the c axis can be used to effectively probe the structure around the Cu-atoms in the ab (horizontal layer) plane as well as in the c (vertical layer) plane.

The performance of two area detectors developed at Brandeis University for structural biology studies is described: a vidiconbased detector designed for laboratory applications and a CCD-based detector designed for use with synchrotron sources. The vidiconbased detector head incorporates fiber optic tapers two image intensifiers and SIT vidicon. The vidicon detector is characterized by measurements of the DOE and the results of tests at a synchrotron beam line are described. The CCD-based detector head incorporates a fiber optic taper two image intensifiers a camera lens and a Videk 1320 X 1035-pixel CCD camera. Measurements of the performance of the image intensifiers several camera lenses and the CCD camera are described. Results of initial tests of this detector at a synchrotron beam line are presented and recent modification to the detector are described.

All optics for five beam lines of Hefei National Synchrotron Radiation Laboratory the second synchrotron accelerator of Chinabuiltsuccessfully are designed and fab ricated almost by Changchun Institute of Opticsand Fine Mechanics. One of five beam lines is a Photoemission experimental beamline. Its optical system consists of two sets of spherical mirrors a spherical grating monochromator and two cylindrical ml rrors. Energy covering range of the system is lOeVl000eV. This paper describts de sign and fabrication of two sets of mirrors with large radii (89meter and 5lrneter). Dimension of fabricated surface of optics is 310X60 mm surface roughness of it Is less than bA RMS figuring accuracy of it is )/1 0 The system operats at bA-i iooA and grazing incidence angle Is 3 degrees. All optics are made of Zerodur. Vertical and horizontal acceptance angles are 2. 5mrad and 20 mrad. respectively. Four mirrors with the same radius (89t of five mirror are arranged straight in a row along the length. The mirrors are able to be used as a toroidal mirror with large dimension (4x3lOmrn) as relative positions of them are adjusted respectively. The design idea of the optical system has novel and unique feature. Fabrication of all xray/EUV op tics for beamline can meet requirements as mentiond above and the optlca have been assembled successfully in the synchrotron radiation beamline and used for photo emission experiment.

Large area Mo/Si and W/Si multilayers used as Bragg reflectors for synchrotron radiation in soft and hard x-ray regions are fabricated using a newly developed alternating-material sputter deposition on 4-inch diameter substrates. Measurements using a surface profiler show a thickness uniformity of better than 1 deviation over the whole area of 4-inch diameter substrate. The reflectivity of the multilayers for CuKa radiation agrees well with theoretical calculations which include film surface roughness and interfacial roughness. The soft x-ray reflectivity measuring system consisting of the plane grating monochrometer and the reflectometer was developed. The Mo/Si multilayers consisting of 30 pairs of 2. 7-nm thick molybdenum and 4-nm thick silicon layers has been showed a peak reflectivity of 46 and a full-width at half-maximum value of 0. 56 nm at a wavelength of 13 nm. A double monochromators using this Mo/Si multilayer has a peak reflectivity of 19 and full-width at half-maximum value of 0. 37 nm at the same wavelength. W/Si multilayers consisting of 200 pairs of 1. 4-nm thick tungsten and 2. 9-nm thick silicon layers show a peak reflectivity of 8. 5 at a 2. 5-nm wavelength. These results show that high-quality multilayers for Bragg reflectors for synchrotron radiation can be fabricated by alternating-material sputter deposition. 1.

A technique for high energy X-ray diffraction aimed at minimizing absorption effects is considered. Problems discussed include diffraction from perfect crystals; defect structure, diffraction profiles, and mosaic crystals; and X-ray diffraction applications.