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Indispensable tool

Description: Synchrotron radiation has become an indispensable research tool for a growing number of scientists in a seemingly ever expanding number of disciplines. We can thank the European Synchrotron Research Facility (ESRF) in Grenoble for taking an innovative step toward achieving the educational goal of explaining the nature and benefits of synchrotron radiation to audiences ranging from the general public (including students) to government officials to scientists who may be unfamiliar with x-ray techniques and synchrotron radiation. ESRF is the driving force behind a new CD-ROM playable on both PCs and Macs titled Synchrotron light to explore matter. Published by Springer-Verlag, the CD contains both English and French versions of a comprehensive overview of the subject.
Date: August 10, 2001
Creator: Robinson, Arthur
Partner: UNT Libraries Government Documents Department

A week of SRI 2003 in San Francisco

Description: The Eighth International Conference on Synchrotron Radiation (SRI 2003) ended its August 25-28 run at the Yerba Buena Center for the Arts in San Francisco with almost as many in attendance as at the beginning. The steady attendance was surely a tribute to the quality of the program and the excitement it generated among the more than 700 registrants who gathered for four days of plenary talks, parallel sessions, and posters, as well as facility tours of the ALS and SSRL on August 29.
Date: September 29, 2003
Creator: Robinson, Art
Partner: UNT Libraries Government Documents Department

The Advanced Light Source: A third-generation Synchrotron Radiation Source

Description: The Advanced Light Source (ALS) at the E.O. Lawrence Berkeley National Laboratory (Berkeley Lab) of the University of California is a ''third-generation'' synchrotron radiation source optimized for highest brightness at ultraviolet and soft x-ray photon energies. It also provides world-class performance at hard x-ray photon energies. Berkeley Lab operates the ALS for the United States Department of Energy as a national user facility that is available 24 hours/day around the year for research by scientists from industrial, academic, and government laboratories primarily from the United States but also from abroad.
Date: August 14, 2002
Creator: Robinson, Arthur L.
Partner: UNT Libraries Government Documents Department

Very high power THz radiation sources

Description: We report the production of high power (20 watts average, {approx} 1 Megawatt peak) broadband THz light based on coherent emission from relativistic electrons. Such sources are ideal for imaging, for high power damage studies and for studies of non-linear phenomena in this spectral range. We describe the source, presenting theoretical calculations and their experimental verification. For clarity we compare this source to one based on ultrafast laser techniques.
Date: October 31, 2002
Creator: Carr, G.L.; Martin, Michael C.; McKinney, Wayne R.; Jordan, K.; Neil, George R. & Williams, G.P.
Partner: UNT Libraries Government Documents Department

Sixth International Conference on X-ray Microscopy

Description: More than 180 participants from around the world crowded the Clark Kerr Campus of the University of California, Berkeley, from August 1-6, 1999 for the Sixth International Conference on X-Ray Microscopy (XRM99). Held every three years since 1983, the XRM conferences have become the primary international forum for the presentation and discussion of advances in high-spatial-resolution x-ray imaging and applications (including the use of x-ray spectroscopic and analytical techniques) in biological and medical sciences, environmental and soil sciences, and materials and surface sciences.
Date: August 23, 1999
Creator: Robinson, Arthur L.
Partner: UNT Libraries Government Documents Department


Description: The NSLS X-Ray Ring is now being operated with a low emittance lattice. The horizontal emittance was reduced to 45 nm-rad from 90 nm-rad at 2.584 GeV while maintaining a vertical emittance of 0.1 nm-rad. The electron beam life-time was unaffected by the emittance reduction because the decrease in the dispersion in the dipole magnets compensate for the higher bunch density in the Touschek effect. The lattice will also be implemented at 2.8 GeV after the strength of the focusing sextupoles is increased. The effect of low emittance operation on the synchrotron radiation users will be discussed.
Date: March 29, 1999
Partner: UNT Libraries Government Documents Department


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

Coherent synchrotron radiation and stability of a short bunch in a compact storage ring

Description: It should be possible to observe coherent synchrotron radiation at millimeter wavelengths in a compact electron storage ring, provided that the bunch can be made sufficiently short. On the other hand, for a short bunch the radiation reaction is so strong that it could cause a longitudinal instability if the current exceeded some threshold. This might cause bunch lengthening, and cut off or reduce the coherent radiation. Using wake fields from simple models of the vacuum chamber, the authors estimate the threshold current for a proposed upgrade of the Brookhaven small x-ray light source, SXLS-Phase 1.
Date: June 1, 1995
Creator: Warnock, R.L. & Bane, K.
Partner: UNT Libraries Government Documents Department

Synchrotron Radiation Computed Tomography (SRCT) of Ruled Laser Targets

Description: High spatial resolution tomography benefits from a high brightness source (photons/(mr{sup 2} x source area)). A synchrotron radiation source provides extremely high continuous brightness with spectral characteristics suited to a wide variety of imaging needs. Therefore, during the initial testing of the new synchrotron radiation computed tomography (SRCT) system at Stanford Synchrotron Radiation Laboratory, it was suggested that we image a ruled target designed for NIF experiments. This is a detailed report of that imaging effort.
Date: March 15, 2002
Creator: Kinney, J H & Haupt, D L
Partner: UNT Libraries Government Documents Department

12th Annual ALS Users' Association Meeting

Description: Science took the front seat as 219 Advanced Light Source (ALS) users and staff gathered on Monday and Tuesday, October 18 and 19 for the twelfth annual users' meeting. The bulk of the meeting was dedicated to reports on science at the ALS. Packed into two busy days were 31 invited oral presentations and 80 submitted poster presentations, as well as time to visit 24 vendor booths. The oral sessions were dedicated to environmental science, chemical dynamics, biosciences, magnetic materials, and atomic and molecular science. In addition, there was an ALS highlights session that emphasized new results and a session comprising highlights from the young scientists who will carry the ALS into the future.
Date: December 17, 1999
Creator: Robinson, Arthur L.
Partner: UNT Libraries Government Documents Department

Workshop on detectors for synchrotron radiation

Description: Forefront experiments in many scientific areas for which synchrotron sources provide sufficient flux are nonetheless hindered because detectors cannot collect data fast enough, do not cover sufficiently solid angle, or do no have adequate resolution. Overall, the synchrotron facilities, each of which represents collective investments from funding agencies and user institutions ranging from many hundreds of millions to more than a billion dollars, are effectively significantly underutilized. While this chronic and growing problem plagues facilities around the world, it is particularly acute in the United States, where detector research often has to ride on the coat tails of explicitly science-oriented projects. As a first step toward moving out of this predicament, scientists from the U.S. synchrotron facilities held a national workshop in Washington, DC, on October 30-31, 2000. The Workshop on Detectors for Synchrotron Research aimed to create a national ''roadmap'' for development of synchrotron-radiation detectors.
Date: November 22, 2000
Creator: Robinson, Arthur L.
Partner: UNT Libraries Government Documents Department

Coherent synchrotron radiation: Theory and experiments

Description: Our understanding of the generation of coherent synchrotron radiation in magnetic bending systems and its impact on beam dynamics has grown considerably over the past few years. The search for understanding has brought a number of surprises, all related to the complexity of the fully self-consistent problem. Herein I survey the associated phenomenology, theory, and experiments while emphasizing important subtleties that have recently been uncovered. I conclude by speculating on courses of future investigations that may prove fruitful.
Date: July 19, 2002
Creator: Bohn, Courtland L.
Partner: UNT Libraries Government Documents Department

Improving and extending performance at synchrotron radiation facilities

Description: Synchrotron radiation facilities around the world have now matured through three generations. The latest facilities have all met or exceeded their design specifications and are learning how to cope with the ever more demanding requests of the user community, especially concerning beam stability. The older facilities remain competitive by extending the unique features of their design, and by developing novel insertion devices. In this paper we survey the beam characteristics achieved at third-generation sources and explore the improvements made at earlier generation facilities.
Date: May 1, 1997
Creator: Jackson, A.
Partner: UNT Libraries Government Documents Department

6 GeV light source project cost estimating procedure

Description: To maintain uniformity in estimating the cost requirements of the various components of the 6 GeV Light Source, the following procedure will be used by all the task groups. The procedure uses a Work Breakdown Structure (VBS) to break down the project into manageable, easy to estimate, components. The project is first broken down into major tasks or categories. Then each major division is continuously subdivided until the desired level of detail is achieved. This can be shown best by using the example of the WBS of the Aladdin Upgrade Project, excerpts of which are included in Appendix A.
Date: October 23, 1985
Partner: UNT Libraries Government Documents Department

Performance of the TLS at SRRC

Description: 3-year operation experiences of the 1.3 GeV synchrotron radiation facility at SRRC are presented. Two insertion devices (W20 and U10p) are installed in the storage ring; more are under construction. Single bunch instabilities were measured and ring impedance calculated. Both transverse and longitudinal coupled bunch instabilities were observed and corresponding feedback system constructed. The transverse feedback system is now routinely operated. A fast global orbit feedback system is in the development stage. Lifetime is about 5 hours at 200 mA; plans to increase lifetime are proposed. At present, the machine can be operated at nominal design energy 1.3 GeV with full energy injection and ramped up to 1.5 GeV at 200 mA.
Date: October 1, 1996
Creator: Liu, Y.C.; Chen, J.R.; Chang, C.H.; Hsu, K.T. & Kuo, C.C
Partner: UNT Libraries Government Documents Department

Innovations in the design of mechanical components for a beamline -- The SRl`95 Workshop 2 summary

Description: The Synchrotron Radiation Instrumentation 1995 Conference (SRI`95) was hosted by the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). Of the many workshops within the conference, the SRI`95 Workshop 2 was ``Innovations in the Design of Mechanical Components of a Beamline``. The workshop was attended well with over 140 registrants. The following topics were discussed. Industry`s perspective on the status and future was provided by Huber Diffrationtechnik, Oxford Instruments, and Kohzu Seiko Ltd. on goniometers/diffractometers, advanced manufacturing technique of high heat load components, such as the APS photon shutter, and the specialties of monochromators provided to the third-generation synchrotrons, respectively. This was followed by a description of the engineering of a dual function monochromator design for water-cooled diamond or cryogenically cooled silicon monochromators by CMC CAT/APS. Another category was the nagging problem of sensitivity of the photon beam position monitors (XBPM) to bending magnet radiation (``BM contamination``) and the undulator magnet gap changes. Problem descriptions and suggested solutions were provided by both the Advanced Light Source (ALS) and the APS. Other innovative ideas were the cooling schemes (enhanced cooling of beamline components using metallic porous meshes including cryo-cooled applications); Glidcop photon shutter design using microchannels at the ALS; and window/filter design, manufacture and operational experiences at CHESS and PETRA/HASYLAB. Additional discussions were held on designing for micromotions and precision in the optical support systems and smart user filter schemes. This is a summary of the presentations at the Workshop. 5 refs., 5 figs.
Date: December 31, 1995
Creator: Kuzay, T.M. & Warwick, T.
Partner: UNT Libraries Government Documents Department

Long wavelength end-effect undulator radiation (Transition Undulator Radiation)

Description: As first pointed out by K.-J. Kim, undulator radiation contains a broad-band component in the long wavelength region. This radiation is due to the change in longitudinal velocity of an electron upon entering and leaving an undulator. The radiation pattern is a hollow cone, peaked in the forward direction, with an opening angle of approximately 1/{gamma}, with a spectrum covering a wide range, including the infra-red and the visible. The radiation is radially polarized, analogous to transition radiation, and exhibits interference effects between the entrance and exit ends of the undulator, similar to the interference effects observed for transition radiation from a thin slab of material. A straightforward application of formulas from Jackson ({ital Classical Electrodynamics}) results in a closed form exact expression for the low frequency limit of this novel radiation effect, Transition Undulator Radiation or TUR. 3 refs., 3 figs.
Date: January 29, 1996
Creator: Kincaid, B.M.
Partner: UNT Libraries Government Documents Department

Recent x-ray observations of intermediate BL Lac objects

Description: We present recent ROSAT, ASCA and SAX observations of intermediate BL Lac objects (IBLs), i.e. BL Lacs which are located between high-energy and low-energy peaked BL Lac objects with respect to log (S<sub>x</sub>/S<sub>r</sub>). Both, the statistical properties of IBLs from the RGB sample and a detailed broad band X-ray spectral analysis of two objects (1424+2401, 1055+5644), point towards a continuous distribution of synchrotron emission peak frequencies among BL Lac objects.
Date: June 1, 1998
Creator: Brinkmann, W; Laurent-Muehleisen, S & Siebert, J
Partner: UNT Libraries Government Documents Department

Two-Color Experiments Combining the UV-Storage Ring Free Electron Laser and SA5 IR Beamline at Super-ACO

Description: This article reviews pump-probe experiments with a storage ring based free-electron laser pump, and synchrotron radiation as a broadband spectroscopic probe.
Date: July 19, 1999
Creator: Nahon, Laurent; Renault, Eric; Couprie, Marie-Emmanuelle; Nutarelli, Daniele; Garzella, David; Billardon, Michel et al.
Partner: UNT Libraries Government Documents Department

Estimates of dispersive effects in a bent NLC Main Linac

Description: An alternative being considered for the Next Linear Collider (NLC) is not to tunnel in a straight line but to bend the Main Linac into an arc so as to follow a gravitational equipotential. The authors begin here an examination of the effects that this would have on vertical dispersion, with its attendant consequences on synchrotron radiation and emittance growth by looking at two scenarios: a gentle continuous bending of the beam to follow an equipotential surface, and an introduction of sharp bends at a few sites in the linac so as to reduce the maximum sagitta produced.
Date: October 31, 2000
Creator: Michelotti, Michael Syphers and Leo
Partner: UNT Libraries Government Documents Department