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Synchrotron radiation interferences between small dipoles at LEP

Description: Synchrotron Radiation interferences between small dipoles in the very low (visible) frequency range have been studied at the LEP diagnostic mini-wiggler. Their understanding allowed a substantial brightness gain by adequate layout modifications. The phenomenon is described analytically in terms of time coherence effects. This serves as a basis for further detailed numerical simulations of the experiment by means of stepwise ray-tracing, and allows precise interpretation of the spectral, polarization and intensity measurements collected at LEP. It also provides guidelines for SR diagnostic at injection energy in LHC.
Date: June 1, 1997
Creator: Bovet, C., Burns, A., Meot, F., Placidi, M., Rossa, E., de Vries, J.
Partner: UNT Libraries Government Documents Department


Description: The mechanical design considerations are discussed with respect to the currently installed X-13 and future X-29 MGU. Comparisons to the previous 2 generations of variable small-gap undulator evolution in the NSLS X-ray ring are made and design improvements noted. The design requirements and mechanical difficulties for holding, positioning and driving the magnetic arrays are explored. Structural, thermal and electrical considerations which influenced the design are then analyzed. The mechanical performance of the MGU currently installed at X-13 is examined and future installations and enhancements are presented.
Date: September 5, 2002
Partner: UNT Libraries Government Documents Department

Installation of a Synchrotron Radiation Beamline Facility at the J. Bennett Johnston Center. Final Report

Description: The Johnston Center presents a unique opportunity for scientists and engineers at southern institutions to initiate and carry out original research using synchrotron radiation ranging from visible light to hard x-rays. The Science and Engineering Alliance proposes to carry out a comprehensive new synchrotron radiation research initiative at CAMD in carefully phased steps of increasing risks. (1) materials research on existing CAMD beam lines and end stations; (2) design, construction and installation of end stations on existing CAMD beam lines, and research with this new instrumentation; (3) design, construction and operation of dedicated synchrotron radiation beam lines that covers the full spectral range of the CAMD storage ring and expanded research in the new facility.
Date: March 21, 2000
Creator: Gooden, R.
Partner: UNT Libraries Government Documents Department

Evolving bunch and retardation in the impedance formalism

Description: The usual expression for the longitudinal wake field in terms of the impedance is exact only for the model in which the source of the field is a rigid bunch. To account for a deforming bunch one has to invoke the complete impedance, a function of both wave number and frequency. A computation of the corresponding wake field would be expensive, since it would involve integrals over frequency and time in addition to the usual sum over wave number. We treat the problem of approximating this field in an example of current interest, the case of coherent synchrotron radiation (CSR) in the presence of shielding by the vacuum chamber.
Date: May 22, 2003
Creator: Warnock, Robert & Venturini, Marco
Partner: UNT Libraries Government Documents Department


Description: Profiling instruments are well-suited to the measurement of grazing incidence optics, such as those found in synchrotron radiation beam lines. Slope measuring profilers, based upon the principle of the pencil beam interferometer, have proven to be especially useful in measuring the figure and slope errors on cylindrical aspheres. The Long Trace Profiler, in various configurations, is the most widely used of this class of profiler. Current performance provides slope measurement accuracy at the microradian level and height measurements accurate to 25 nm over 1 meter trace lengths.
Date: January 14, 2003
Creator: TAKACS,P.Z.
Partner: UNT Libraries Government Documents Department

Ring Energy Selection and Extra Long Straight Sections for the Advanced Photon Source

Description: Recommended criteria are given for the performance of Advanced Photon Source (APS), taking into consideration undulator tunability criteria and their relationship to the storage ring energy and undulator gap, length of straight sections.
Date: April 1987
Creator: Brown, G.; Cho, Y.; Hastings, J.; Krinsky, S.; Moncton, D. E.; Shenoy, G. K. et al.
Partner: UNT Libraries Government Documents Department

Insertion Device and Beam Line Plans for the Advanced Photon Source : a Report and Recommendations by the Insertion Device and Beam Line Planning Committee

Description: In the 7-GeV Advanced Photon Source (APS) Conceptual Design Report (CDR), fifteen complete experimental beam lines were specified in order to establish a representative technical and cost base for the components involved. In order to optimize the composition of the insertion devices and the beam line, these funds are considered a ''Trust Fund.'' The present report evaluates the optimization for the distribution of these funds so that the short- and long-term research programs will be most productive, making the facility more attractive from the user's point of view. It is recommended that part of the "Trust Fund" be used for the construction of the insertion devices, the front-end components, and the first-optics, minimizing the cost to potential users of completing a beam line. In addition, the possibility of cost savings resulting from replication and standardization of high multiplicity components (such as IDs, front ends, and first-optics instrumentation) is addressed.
Date: February 1987
Creator: Boyce, R.; Hewitt, R.; Morrison, T. I.; Shenoy, G. K.; Thomlinson, W. & Viccaro, P. J.
Partner: UNT Libraries Government Documents Department

An Overview of the Characteristics of the 6-GeV Synchrotron Radiation : a Preliminary Guide for Users

Description: In this document we present the characteristics of the electromagnetic radiation from various types of sources on a 6-GeV storage ring. The sources include bending magnets, undulators and wigglers. The characteristics are compared with those of other synchrotron sources when operated at their design specifications. The influence of positron beam size on the brilliance is discussed, along with the power distribution from these sources. The goal of this document is to provide users with enough information on the behavior of radiation from a 6-GeV storage ring so that a dialogue can be established with the accelerator physicists and engineers to achieve an optimal design.
Date: October 1985
Creator: Shenoy, G. K. & Viccaro, P. J.
Partner: UNT Libraries Government Documents Department

Looking Back at International Synchrotron Radiation Instrumentation

Description: With the 11th International Synchrotron Radiation Instrumentation coming up in July 2012 in Lyons, France, we thought it might be of interest to our readers to review all the past meetings in this series. We thank Denny Mills of the APS, Argonne for putting the list together. Prior to these larger meetings, and in the early days, facilities held their own meetings similar to the user meetings of today. However, the meeting held at ACO in Orsay, France in 1977 was the first such meeting with an international flavor and so it is on the list. However it is not counted as number 1 since it was agreed way back to start the numbering with the 1982 DESY meeting. The 2005 USA National Meeting scheduled at CAMD in Baton Rouge had to be canceled due to Hurricane Katrina. It was ultimately held in 2007, with the CLS hosted meeting the following year. And a personal note from the magazine - Synchrotron Radiation News was born at the 1987 meeting in Madison, Wisconsin with a proposal that was put to a special session of the meeting organized by Susan Lord. Initial proposals were to model it after the CERN Courier, but it soon adopted its own distinct flavor.
Date: March 1, 2012
Creator: Williams, Gwyn
Partner: UNT Libraries Government Documents Department


Description: We discuss the possibility of using synchrotron radiation to form electron rings having a very high electric field to hold the ions inside the ring. The formulas describing bow the energy and the dimension of the ring change under the effect of synchrotron radiation are derived, and a numerical example is given.
Date: May 13, 1970
Creator: Pellegrini, C.
Partner: UNT Libraries Government Documents Department

Some Aspects of the Two Beam Performance of DCI

Description: The results of beam-beam simulations that model DCI operating as an e{sup +}e{sup -} collider are reported. The simulation techniques, including a new procedure for incorporating synchrotron radiation, are described. Phase advance errors between the interaction points explain the beam-beam limit at the operating point q{sub x} = q{sub y} = 0.725 (q denotes the fractional part of the tune). The effects of radiation damping are also studied near that operating point. Simulation and experiments disagree in a second operating region, q{sub x} = q{sub y} {approx} 0.795, indicating additional physics outside the scope of our model.
Date: September 1, 1991
Creator: Krishnagopal, S. & Siemann, R.H.
Partner: UNT Libraries Government Documents Department

Enabling instrumentation and technology for 21st century light sources

Description: We present the summary from the Accelerator Instrumentation and Technology working group, one of the five working groups that participated in the BES-sponsored Workshop on Accelerator Physics of Future Light Sources held in Gaithersburg, MD September 15-17, 2009. We describe progress and potential in three areas: attosecond instrumentation, photon detectors for user experiments, and insertion devices.
Date: June 1, 2010
Creator: Byrd, J.M.; Shea, T.J.; Denes, P.; Siddons, P.; Attwood, D.; Kaertner, F. et al.
Partner: UNT Libraries Government Documents Department

An Isochronous Lattice for PEP

Description: With e{sup +}e{sup -} storage rings operating in a quasi-isochronous mode, it might be possible to produce short bunches with length {sigma}{sub z} < 1 cm. The unique characteristics of the short bunches could then be utilized for synchrotron radiation applications or colliders with mm-scale {beta}*. In principle, the design of a quasi-isochronous storage ring is relatively straight-forward, but experimental studies with electron storage rings in this configuration have not been carried out. The purpose of this paper is to demonstrate that an isochronous lattice design is compatible with PEP given a minimum of hardware modifications.
Date: April 1, 1991
Creator: Corbett, W.J.; Donald, M.H.R. & Garren, A.A.
Partner: UNT Libraries Government Documents Department

Wake fields and energy spread for the ERHIC ERL

Description: Wake fields in high-current ERLs can cause significant beam quality degradations. Here we summarize effects of coherent synchrotron radiation, resistive wall, accelerating cavities and wall roughness for ERL parameters of the eRHIC project. A possibility of compensation of such correlated energy spread is also presented. An emphasis in the discussion is made on the suppression of coherent synchrotron radiation due to shielding and a possible reduction of wall roughness effects for realistic surfaces.
Date: October 16, 2011
Creator: V., Fedotov A.; Kayran&#44 & D.
Partner: UNT Libraries Government Documents Department

A Vlasov solver for collective effects in particle accerators

Description: Integration techniques based on Lie algebraic methods have been successfully used in beam transport codes for particle accelerators. Generally these methods have been applied to problems of single-particle beam dynamics. Here we present an application of Lie algebraic techniques to the development of a Vlasov solver suitable for problems of beam transport in the presence of non-negligible particle self-fields. The solver we discuss is suitable for modelling a variety of collective effects that may arise at high current. In particular, we consider the case of coherent synchrotron radiation effects in magnetic bunch compressors which can cause instabilities limiting performance of high current accelerators.
Date: February 1, 2009
Creator: Migliorati, M.; Schiavi, A.; Dattoli, G. & Venturini, M.
Partner: UNT Libraries Government Documents Department

Keck Observations of the 2002-2003 Jovian Ring Plane Crossing

Description: We present new observations of Jupiter's ring system at a wavelength of 2.2 {micro}m obtained with the 10-m W. M. Keck telescopes on three nights during a ring plane crossing: UT 19 December 2002, and 22 and 26 January 2003. We used conventional imaging, plus adaptive optics on the last night. Here we present detailed radial profiles of the main ring, halo and gossamer rings, and interpret the data together with information extracted from radio observations of Jupiter's synchrotron radiation. The main ring is confined to a 800-km-wide annulus between 128,200 and 129,000 km, with a {approx} 5000 km extension on the inside. The normal optical depth is 8 x 10{sup -6}, 15% of which is provided by bodies with radii a {approx}> 5 cm. These bodies are as red as Metis. Half the optical depth, {tau} {approx} 4 x 10{sup -6}, is attributed to micron-sized dust, and the remaining {tau} {approx} 3 x 10{sup -6} to grains tens to hundreds of {micro}m in size. The inward extension consists of micron-sized (a {approx}< 10 {micro}m) dust, which probably migrates inward under Poynting-Robertson drag. The inner limit of this extension falls near the 3:2 Lorentz resonance (at orbital radius r = 122,400 km), and coincides with the outer limit of the halo. The gossamer rings appear to be radially confined, rather than broad sheets of material. The Amalthea ring is triangularly shaped, with a steep outer dropoff over {approx} 5000 km, extending a few 1000 km beyond the orbit of Amalthea, and a more gradual inner dropoff over 15,000-20,000 km. The inner edge is near the location of the synchronous orbit. The optical depth in the Amalthea ring is {approx} 5 x 10{sup -7}, up to 20% of which is comprised of macroscopic material. The optical depth in the Thebe ring ...
Date: November 29, 2007
Creator: de Pater, I; Showalter, M R & Macintosh, B A
Partner: UNT Libraries Government Documents Department


Description: The Long Trace Profiler (LTP) is a useful optical metrology instrument for measuring the figure and slope error of cylindrical aspheres commonly used as synchrotron radiation (SR) optics. It is used extensively at a number of synchrotron radiation laboratories around the world. In order to improve SR beam line quality and resolution, the National Synchrotron Radiation Laboratory (NSRL) of China is developing a versatile LTP that can be used to measure both SR optics and more conventional ''normal'' optical surfaces. The optical metrology laboratories at Brookhaven National Laboratory (BNL) and NSRL are collaborating in developing a multiple functions LTP (LTP-MF). Characteristics of the LTP-MF are: a very compact and lightweight optical head, a large angular test range ({+-} 16 mad) and high accuracy. The LTP-MF can be used in various configurations: as a laboratory-based LTP, an in-situ LTP or penta-prism LTP, as an angle monitor, a portable LTP, and a small radius of curvature test instrument. The schematic design of the compact optical head and a new compact slide are introduced. Analysis of different measurements modes and systematic error correction methods are introduced.
Date: July 31, 2005
Creator: QIAN, S.; WANG, Q.; HONG, Y. & TAKACS, P.
Partner: UNT Libraries Government Documents Department

Monitoring performance of the Advanced Light Source

Description: Providing high quality light to users in a consistent and reliable manner is one of the main goals of the accelerator physics group at the Advanced Light source (ALS). To meet this goal considerable time is spent monitoring the performance of the machine. At the Group's weekly meeting the performance of the accelerator over the previous week's run is reviewed. This paper describes the parameters that are monitored to optimize the performance of the ALS.
Date: June 13, 2001
Creator: Byrne, Warren E.; Lampo, Edward J. & Samuelson, Bruce C.
Partner: UNT Libraries Government Documents Department

Concentration of synchrotron beams by means of monolithic polycapillary x-ray optics

Description: Capillary Optics have proven to be a valuable tool for concentrating synchrotron radiation. Single tapered capillaries are used at several facilities. However, most of these optics collect only over a small area. this can be overcome by using larger capillary structures. Polycapillary optics can deflect x-rays by larger angles than other x-ray optics that use only one or two reflections. Conventional x-ray optics that achieve similar deflections, are much more energy selective than capillaries. Therefore, capillaries achieve very short focal distances for a wide range of energies. The measurements shown here represent first tests performed with polycapillaries of large input diameter. The performance with respect to transmission efficiency and spot size was evaluated for a set of four very different prototypes. It is shown that a significant gain may be achieved if a spot size of the order of 0.1 mm is required. Further, some characteristics of the different optics are discussed.
Date: August 1, 1995
Creator: Ullrich, J.B.; Klotzko, I.L.; Huang, K.G.; Owens, S.M.; Aloisi, D.C.; Hofmann, F.A. et al.
Partner: UNT Libraries Government Documents Department