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THE REVITALIZED NSLS VUV RING.

Description: A status report on the revitalization of the NSLS VUV ring will be presented, concentrating on three areas: (1) the four infrared ports (U2A/B, U4IR, U10A/B, and U12IR), (2) conversion of out-of-date toroidal grating monochromators to spherical grating type (U4A, U7A, and U12A), and (3) new insertion device beamlines (U5UA and U13UB). All of these beamlines were designed (new ones) or upgraded (old ones) to serve a specific scientific need represented by the PRTs (both NSLS and non-NSLS based) involved. Therefore, an overview of the scientific programs served by these new beamlines will be given, as well as a summary of the beamline optical designs and operating performance.
Date: October 13, 1999
Creator: HULBERT,S.L.
Partner: UNT Libraries Government Documents Department

THEORETICAL STUDY OF OPTICAL PROPERTIES. APPENDIX B: MONOCHROMATIC ABSORPTION COEFFICIENTS FOR HYDROGEN, BERYLLIUM, AND CARBON. Final Report

Description: No abstract.<><DSN>16:004155<ABS>No abstract.<><DSN>16:004156<ABS>Nitrosylium hexafluoroniolybdate(V) and nitrosylium hexafluorouranate(V) were prepared and characterized. These compounds were prepared by the reaction of nitric oxide with the respective hexafluoride. Nitric oxide did not react with tungsten hexafliioride. Nitrous oxide was found to be unreactive toward molybdenum, tungsten, and uranium hexafluorides. (auth)
Date: September 1, 1961
Creator: Stewart, J C & Pyatt, Jr, K D
Partner: UNT Libraries Government Documents Department

Technical Report on DOE project: X-ray physics of materials (proposal No.Z817)

Description: The SRI-CAT was able to order the construction of the First Optics Enclosure, the second enclosure housing the monochromator and the first user station, and various motors, controllers, and electronics for the control of the hard x-ray beamline components.
Date: January 1, 2001
Creator: Colella, Roberto & Durbin, Stephen
Partner: UNT Libraries Government Documents Department

Why cryogenically cooled, thin crystals handle extremely high power densities

Description: Recently, a new type of cryogenically cooled high heat load monochromator was proposed and, developed at Argonne National Laboratory and tested at European Synchrotron Radiation Facility (ESRF.) These tests showed that powers of 153 W and power densities of 450 W/mm{sup 2} cause only negligible strain. These powers and power densities are larger than will be absorbed by the first crystal on an undulator beamline at the Advanced Photon Source (APS). In our earlier work we suggested that the crystal might show strain at much lower values of the powers and power densities. We now can explain the ESRF results in terms of the unique role the negative thermal expansion coefficient of Si plays in minimizing strain.
Date: September 1, 1995
Creator: Knapp, G.S.; Jennings, G. & Beno, M.A.
Partner: UNT Libraries Government Documents Department

Laterally graded multilayer double-monochromator.

Description: The authors describe a tunable multilayer monochromator with an adjustable bandpass to be used for reflectivity and grazing incidence diffraction studies on surfaces at energies near 10 keV. Multilayers have a bandpass typically 100 times larger than the Si(111) reflection, and by using multilayers an experimenter can significantly increase data collection rates over those available with a Si monochromator. The transmission through 1 and 2 laterally graded multilayer (LGML) reflections was recorded versus photon energy. The identical LGMLs were comprised of 60 bilayers of W and C on 100 x 25 x 3 mm float glass with a bilayer spacing varying from 35 to 60 {angstrom}. The average gradient was 0.27 {angstrom}/mm along the long dimension. The rms deviation of the data for the bilayer spacing from a linear fit was 0.36 {angstrom}. Data were obtained for a nondispersive ({+-}) double-multilayer arrangement. The relative bandpass width (FWHM) when the two multilayers exposed the same bilayer spacing was measured to be 2.2% with a transmission of 78.7 {+-} 1.6%. This value is consistent with the transmission of 88.9% that they also measured for a single LGML at HASYLAB beamline D4. The bandpass was tunable in the range 1.1% to 2.2%.
Date: September 1, 1999
Creator: Als-Nielsen, J.; Erdmann, J.; Gaarde, P.; Krasnicki, S.; Liu, C.; Macrander, A. T. et al.
Partner: UNT Libraries Government Documents Department

Final report: DOE Grant ''Development of focusing monochromators for neutron scattering instruments'' (DE-FG02-96ER45599)

Description: Bent crystal monochromators were developed for the neutron scattering community: (1) doubly focusing bulk silicon, for high-resolution neutron diffraction; (2) doubly focusing multi-wafer silicon, for residual stress instruments; (3) silicon-wafer: (a) with pneumatic spherical bending, (b) with mechanical cylindrical bending, (c) with mechanical two-dimensional bending, for high-resolution three-axis spectrometry; (4) doubly focusing multi-wafer silicon, for epithermal (eV range) neutrons; (5) doubly focusing composite pyrolytic graphite (low-cost), for high-flux applications.
Date: March 21, 2000
Creator: Popovici, Mihai P.
Partner: UNT Libraries Government Documents Department

Pulsed X-ray Characterization of Stripline Micro-Channel Plate Gated Imager

Description: We report on characterization of x-ray imaging arrays developed by National Security Technologies, LLC. These devices are based on a microchannel plate (MCP) with a conventional glass microchannel structure, but the top and bottom conductive coatings, rather than covering the entire area, are configured into several (4 to 8) parallel strips. Since the bias voltage is a pulse launched from one end, these operate as striplines; relative delays between these pulses give different active exposure times. Unlike the case of a static bias voltage, non-uniformities in impedance along a stripline will produce spatial fluctuations in the bias voltage. These are expected to be slight, but the very sensitive dependence of gain on voltage - approximately like Vl/4d, where l and d are the length and diameter of the channel - means there may be very significant spatial non-uniformities in gain. Flat-field calibrations are therefore required so that such effects can be unfolded from the raw images if quantitative data is required. Such flat-field and other characterization measurements, e.g. responsivity and linearity, have therefore been done with a flash X-ray radiographic system. The maximum endpoint energy is 500 keV. The duration is {approx}40 ns, and so is essentially flat (temporally) during the MCP stripline transit time, which is a maximum of 600 ps. Spatial variations are significant, but the data are corrected using independent flat-field measurements. A monochromator selects a particular X-ray transition line (typically K{alpha}) of the anode material, so that characterizations can be done for various well-defined input photon energies.
Date: March 30, 2011
Creator: F. J. Goldin, D. V. Morgan, K. J. Moy
Partner: UNT Libraries Government Documents Department

Paraxial SGM beamlines for coherence experiments at the Advanced Light Source

Description: Beamlines have been designed for coherence experiments at the ALS based on brightness preserving spherical grating monochromators. The operation is almost paraxial so that a very simple scheme can deliver the modest spectral resolution required, with just two focusing optics, one of which is the spherical grating.
Date: July 24, 2008
Creator: Warwick, Anthony I; Warwick, Anthony I & Howells, Malcolm
Partner: UNT Libraries Government Documents Department

A variable-focus x-ray compound lens.

Description: Design and fabrication of an x-ray lens assembly for focusing x-ray beams is described. The assembly consists of a number of precisely stacked and aligned aluminum parts. These parts are cut from a long extruded section having sixteen parabolic cavities along its length. The thickness of the wall between adjacent cavities is 0.2 mm. By cutting the assembled parts diagonally as shown below, a variable-focus lens system can be made. Moving the lens horizontally allows the incident beam to pass through fewer or more cavities, collimating or focusing the emerging beam at a desired distance downstream. The variable focus aluminum lens has been used at the Advanced Photon Source to collimate a monochromatic, 81 keV undulator beam to increase downstream crystal monochromator throughput. Results indicate collimation consistent with theoretical expectations.
Date: October 29, 2002
Creator: Khounsary, A.; Shastri, S. D. & Macrander, A.
Partner: UNT Libraries Government Documents Department

Brilliance and flux reduction in imperfect inclined crystals

Description: The inclined crystal geometry has been suggested as a method of reducing the surface absorbed power density of high-heat-load monochromators for third-generation synchrotron radiation sources. Computer simulations have shown that if the crystals are perfectly aligned and have no strains then the diffraction properties of a pair of inclined crystals are very similar to a pair of conventional flat crystals with only subtle effects differentiating the two configurations. However, if the crystals are strained, these subtle differences in the behavior of inclined crystals can result in large beam divergences causing brilliance and flux losses. This manuscript elaborates on these issues and estimates potential brilliance and flux losses from strained inclined crystals at the APS.
Date: January 1, 1996
Creator: Lee, W.K.; Blasdell, R.C.; Fernandez, P.B.; Macrander, A.T. & Mills, D.M.
Partner: UNT Libraries Government Documents Department

Further tests on liquid-nitrogen-cooled, thin silicon-crystal monochcromators using a focused wiggler synchrotron beam

Description: A newly designed, cryogenically cooled, thin Si crystal monochromator was tested at the European Synchrotron Radiation Facility (ESRF) beamline BL3. It exhibited less than 1 arcsec of thermal strain up to a maximum incident power of 186 W and average power density of 521 W/mm{sup 2}. Data were collected for the thin (0.7 mm) portion of the crystal and for the thick (>25 mm) part. Rocking curves were measured as a function of incident power. With a low power beam, the Si(333) rocking curve at 30 keV for the thin and thick sections was < 1 arcsec FWHM at room temperature. The rocking curve of the thin section increased to 2.0 arcsec when cooled to 78 K, while the thick part was unaffected by the reduction in temperature. The rocking curve of the thin section broadened to 2.5 arcsec FWHM and that of the thick section broadened to 1.7 arcsec at the highest incident power. The proven range of performance for this monochromator has been extended to the power density, but not the absorbed power, expected for the Advanced Photon Source (APS) undulator A in closed-gap operation (first harmonic at 3.27 keV) at a storage-ring current of 300 mA.
Date: January 1, 1996
Creator: Rogers, C.S.; Mills, D.M. & Fernandez, P.B.
Partner: UNT Libraries Government Documents Department

An elliptical wiggler beamline for the ALS

Description: A beamline for circularly polarized radiation produced by an elliptical wiggler has been designed at the ALS covering the broad energy range from 50 eV to 2000 eV. The rigorous theory of grating diffraction efficiency has been used to maximize transmitted flux. The nature of the elliptical wiggler insertion device creates a challenging optical problem due to the large source size in the vertical and horizontal directions. The requirement of high resolving power, combined with the broad tuning range and high heat loads complicate the design. These problems have been solved by using a variable included angle monochromator of the ``constant length`` type with high demagnification onto its entrance slit, and cooled optics.
Date: October 1, 1995
Creator: Martynov, V.V.; McKinney, W.R. & Padmore, H.A.
Partner: UNT Libraries Government Documents Department

Development of a monochromator system for the APS X-ray BESSRC beamlines

Description: The authors have designed a double crystal, fixed exit monochromator which allows windowless operation of the APS beamlines. The crystals are mounted on a turntable with the first crystal at the center of rotation. A mechanical linkage is used to correctly position the second crystal and maintain a constant offset. The monochromator is designed with two adjacent vacuum chambers, one containing the drive mechanism, a vacuum compatible Huber goniometer, and another chamber containing a turntable on which the monochromator linkage and crystals are mounted. The small annular opening around a hollow stainless steel shaft which connects the Huber goniometer to the turntable is the only passage between the two adjacent chambers. The design of the monochromator is such that it can accommodate water, liquid nitrogen or galium cooling for the crystal optics. The basic design for the monochromator linkage mechanism is presented along with details of the monochromator chamber. The results of initial optical tests of the monochromator system using tilt sensors and a precision autocollimator will also be given.
Date: March 1, 1997
Creator: Beno, M.A.; Knapp, G.S. & Ramanathan, M.
Partner: UNT Libraries Government Documents Department

Progress in silicon-to-silicon direct bonding and its application to synchrotron x-ray optics

Description: X-ray optical elements (such as single-crystal silicon monochromators) illuminated with high-power synchrotron-radiation beams produced by insertion devices and, to a lesser extent bending magnets, require cooling, When operating a silicon crystal at room temperature, channels for the coolant are often fabricated directly beneath the diffracting surface. Then a separate silicon distribution manifold/plenum is manufactured, and the components are bonded together using an adhesive or some intermediate material. In many cases, such monochromators suffer from strains induced by the bond. A silicon-to-silicon direct-bonding technique (i.e., without any intermediate material) has been developed that appears to be an attractive method for creating a bond with less strain between two pieces of silicon. This technique is well understood for the case of thin wafers ({approximately}0.5 mm thickness) and is used by the semiconductor industry. Recently, bonding of 16-mm-thick 10-cm-diameter silicon crystals has been successfully performed inducing very little strain. A short review of the silicon-to-silicon crystals has been successfully performed inducing very little strain. A short review of the silicon-to-silicon direct-bonding process will be presented with an emphasis on its application to room temperature high-heat-load x-ray optics with the present status of direct bonding efforts at the APS.
Date: February 1, 1997
Creator: Graber, T.; Krasnicki, S. & Fernandez, P.B.
Partner: UNT Libraries Government Documents Department

Design and performance of the ALS double-crystal monochromator

Description: A new ``Cowan type`` double-crystal monochromator, based on the boomerang design used at NSLS beamline X-24A, has been developed for beamline 9.3.1 at the ALS, a windowless UHV beamline covering the 1-6 keV photon-energy range. Beamline 9.3.1 is designed to simultaneously achieve the goals of high energy resolution, high flux, and high brightness at the sample. The mechanical design has been simplified, and recent developments in technology have been included. Measured mechanical precision of the monochromator shows significant improvement over existing designs. In tests with x-rays at NSLS beamline X-A, maximum deviations in the intensity of monochromatic light were just 7% during scans of several hundred eV in the vicinity of the Cr K edge (6 keV) with the monochromator operating without intensity feedback. Such precision is essential because of the high brightness of the ALS radiation and the overall length of beamline 9.3.1 (26 m).
Date: August 1, 1994
Creator: Jones, G.; Ryce, S.; Perera, R.C.C.; Lindle, D.W.; Karlin, B.A. & Woicik, J.C.
Partner: UNT Libraries Government Documents Department

Further tests on liquid-nitrogen-cooled, thin silicon-crystal monochromators using a focused wiggler synchrotron beam

Description: A newly designed cryogenically cooled, thin Si crystal monochromator was tested at the European Synchrotrons Radiation Facility (ESRF) beamline BL3. It exhibited less than 1 arcsec of thermal strain up to a maximum incident power of 186 W and average power density of 521 W/mm{sup 2}. Data were collected for the thin (0.7 mm) portion of the crystal and for the thick (&gt;25 mm) part. Rocking curves were measured as a function of incident power. With a low power beam, the Si(333) rocking curve at 30 keV for the thin and thick sections was &lt; 1 arcsec FWHM at room temperature. The rocking curve of the thin section increased to 2.0 arcsec when cooled to 78 K, while the thick part was unaffected by the reduction in temperature. The rocking curve of the this section broadened to 2.5 arcsec FWHM and that of the thick section broadened to 1.7 arcsec at the highest incident power. The proven range of performance for this monochromator has been extended to the power density, but not the absorbed power, expected for the Advanced Photon Source (APS) undulator A in closed-gap operation (first harmonic at 3.27 kev) at a storage-ring current of 300 mA.
Date: May 9, 2000
Creator: Rogers, C. S.; Mills, D. M.; Fernandez, P. B.; Knapp, G. S.; Wulff, M.; Hanfland, M. et al.
Partner: UNT Libraries Government Documents Department

A high-precision cryogenically-cooled crystal monochromator for the APS diagnostics beamline

Description: A high-precision cryogenically-cooled crystal monochromator has been developed for the APS diagnostics beamline. The design permits simultaneous measurements of the particle beam size and divergence. It provides for a large rotation angle, {minus}15{degree} to 180{degree}, with a resolution of 0.0005{degree}. The roll angle of the crystal can be adjusted by up to {+-}3{degree} with a resolution of 0.0001{degree}. A vertical translational stage, with a stroke of {+-}25 mm and resolution of 8 {micro}m, is provided to enable using different parts of the same crystal or to retract the crystal from the beam path. The modular design will allow optimization of cooling schemes to minimize thermal distortions of the crystal under high heat loads.
Date: July 24, 2000
Creator: Rotela, E.; Yang, B.; Sharma, s. & Barcikowski, A.
Partner: UNT Libraries Government Documents Department

Optical design for laser Doppler angular encoder with sub-nanoradian sensitivity

Description: A novel laser angular encoder system has been developed based on the principles of radar, the Doppler effect, optical heterodyning, and self aligning multiple reflection optics. Using this novel three dimensional multiple reflection optical path, a 10 to 20 times better resolution has been reached compared to commercially available laser Doppler displacement meters or laser interferometer systems. With the new angular encoder, sub-nanoradian resolution has been attained in the 8 degree measuring range in a compact setup about 60 mm (H) x 150 mm (W) x 370 mm (L) in size for high energy resolution applications at the Advanced Photon Source undulator beamline 3-ID.
Date: September 1, 1997
Creator: Shu, D.; Alp, E.E.; Barraza, J.; Kuzay, T.M. & Mooney, T.
Partner: UNT Libraries Government Documents Department

Design of a high-resolution high-stability positioning mechanism for crystal optics

Description: The authors present a novel miniature multi-axis driving structure that will allow positioning of two crystals with better than 50-nrad angular resolution and nanometer linear driving sensitivity.The precision and stability of this structure allow the user to align or adjust an assembly of crystals to achieve the same performance as does a single channel-cut crystal, so they call it an artificial channel-cut crystal. In this paper, the particular designs and specifications, as well as the test results,for a two-axis driving structure for a high-energy-resolution artificial channel-cut crystal monochromator are presented
Date: October 11, 1999
Creator: Shu, D.; Toellner, T. S. & Alp, E. E.
Partner: UNT Libraries Government Documents Department

Second crystal cooling on cryogenically cooled undulator and wiggler double crystal monochromators.

Description: Simple methods for the cooling of the second crystals of cryogenically cooled undulator and wiggler double crystal monochromators are described. Copper braids between the first and second crystals are used to cool the second crystals of the double crystal monochromators. The method has proved successful for an undulator monochromator and we describe a design for a wiggler monochromator.
Date: August 3, 1998
Creator: Knapp, G. S.
Partner: UNT Libraries Government Documents Department

Performance of cryogenically cooled, high-heat-load silicon crystal monochromators with porous media augmentation

Description: The performance of two Si crystal x-ray monochromators internally cooled with liquid nitrogen was tested on the F2-wiggler beamline at the Cornell High Energy Synchrotron Source (CHESS). Both crystals were (111)-oriented blocks of rectangular cross section having identical dimensions. Seven 6.4-mm-diameter coolant channels were drilled through the crystals along the beam direction. In one of the crystals, porous Cu mesh inserts were bonded into the channels to enhance the heat transfer. The channels of the second crystal were left as drilled. Symmetric, double-crystal rocking curves were recorded simultaneously for both the first and third order reflections at 8 and 24 keV. The power load on the cooled crystal was adjusted by varying the horizontal beam size using slits. The measured Si(333) rocking curve of the unenhanced crystal at 24 keV at low power was 1.9 arcsec FWHM. The theoretical width is 0.63 arcsec. The difference is due to residual fabrication and mounting strain. For a maximum incident power of 601 W and an average power density of about 10 W/MM{sup 2}, the rocking curve was 2.7 arcsec. The rocking curve for the enhanced crystal at low power was 2.4 arcsec. At a maximum incident power of 1803 W and an average power density of about 19 W/mm{sup 2} the rocking curve width was 2.2 arcsec FWHM. The use of porous mesh augmentation is a simple, but very effective, means to improve the performance of cryogenically cooled Si monochromators exposed to high power x-ray beams.
Date: January 1, 1996
Creator: Rogers, C.S.; Mills, D.M.; Assoufid, L. & Graber, T.
Partner: UNT Libraries Government Documents Department