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in subjects: "Beam Dynamics, Field Calculations, And Ion Optics"  
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The ANL X6B Beamline at NSLS: A Versatile Facility

Description: We have described the x-ray optics and beamline performance of the ANL X6B beam line at the NSLS. Considerable flexibility has been built into the beam line to accommodate a wide range of x-ray diffraction, scattering, and spectroscopy experiments with various requirements. We presented selected examples of experimental results and showed that with the high intensity, high energy resolution, high-q resolution, and energy tunability, the X6B beam line has become a versatile facility.
Date: July 1, 1994
Creator: Huang, K. G.; Ramanathan, M. & Montano, P. A.
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Partner: UNT Libraries Government Documents Department
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Incorporation of an elliptical boundary condition into the program POISSON

Description: This report is the third in a series which takes into account the boundary condition in electromagnetic problems such as used by the program POISSON. Here we extend the analysis to permit the use of an elliptical boundary both for two-dimensional and ax
Date: December 1, 1984
Creator: Caspi, S.; Helm, M. & Laslett, L.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Nonlinear beam dynamics experimental program at SPEAR

Description: Since nonlinear effects can impose strict performance limitations on modern colliders and storage rings, future performance improvements depend on further understanding of nonlinear beam dynamics. Experimental studies of nonlinear beam motion in three-dimensional space have begun in SPEAR using turn-by-turn transverse and longitudinal phase-space monitors. This paper presents preliminary results from an on-going experiment in SPEAR.
Date: March 1, 1995
Creator: Tran, P.; Pellegrini, C.; Cornacchia, M.; Lee, M. & Corbett, W.
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Partner: UNT Libraries Government Documents Department
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Moment approach to high-order accelerator beam optics

Description: High-current beams must be matched to high order to minimize emittance growth and particle losses. For matching problems, the moment approach, in which the author describes the particle beam by the moments of its distributions, is particularly valuable. A variety of analytical results are available for linear motion. The moment approach is also the basis of the 3-D space-charge simulation code BEDLAM, in which the dynamical variables are the moments. Moment simulation codes are particularly use… more
Date: October 1, 1994
Creator: Lysenko, W. P.
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Partner: UNT Libraries Government Documents Department
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Laser cooling of {sup 24}Mg{sup +} in the ASTRID storage ring

Description: Laser cooling of {sup 24}Mg{sup +} has now begun at the ASTRID storage ring. In contrast to {sup 7}Li{sup +}, which has been used up to now, it is now possible for the laser to interact with all of the beam. In this paper some of the results from the first beam time with {sup 24}Mg{sup +} are described. By frequency chirping a single laser, laser cooling has been performed on a coasting beam, and first evidence of sympathetic transverse cooling has been observed.
Date: May 1, 1994
Creator: Nielsen, J. S.; Hangst, J. S.; Poulsen, O.; Shi, P.; Schiffer, J. P. & Wanner, B.
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Partner: UNT Libraries Government Documents Department
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Self-consistent beam halo studies & halo diagnostic development in a continuous linear focusing channel

Description: Beam halos are formed via self-consistent motion of the beam particles. Interactions of single particles with time-varying density distributions of other particles are a major source of halo. Aspects of these interactions are studied for an initially equilibrium distribution in a radial, linear, continuous focusing system. When there is a mismatch, it is shown that in the self-consistent system, there is a threshold in space-charge and mismatch, above which a halo is formed that extends to {app… more
Date: December 1, 1994
Creator: Jameson, R. A.
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Partner: UNT Libraries Government Documents Department
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The cooling of particle beams

Description: A review is given of the various methods which can be employed for cooling particle beams. These methods include radiation damping, stimulated radiation damping, ionization cooling, stochastic cooling, electron cooling, laser cooling, and laser cooling with beam coupling. Laser Cooling has provided beams of the lowest temperatures, namely 1 mK, but only for ions and only for the longitudinal temperature. Recent theoretical work has suggested how laser cooling, with the coupling of beam motion, … more
Date: October 1, 1994
Creator: Sessler, A. M.
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Partner: UNT Libraries Government Documents Department
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Polarized nature of synchrotron radiation

Description: Synchrotron radiation is inherently highly polarized, and this fact makes synchrotron radiation useful for probing the directional and/or helical nature of the matter via polarization sensitive experiment. Here we summarize briefly the nature of the polarization experiments and the polarization characteristics of synchrotron radiation. 12 refs., 3 figs.
Date: September 1, 1991
Creator: Kim, K. J.
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Partner: UNT Libraries Government Documents Department
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Beam Loading in a High Current Accelerating Gap

Description: Energy exchange between a high-current beam and a source at an accelerating gap is treated with a simple transmission line theory. There exists a matching condition for which the beam energy gain is equal to the source voltage. The total energy gain in a multigap system is expressed in terms of individual source voltages and the beam current.
Date: December 31, 1991
Creator: Rhee, M. J. & Ding, B. N.
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Partner: UNT Libraries Government Documents Department
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Crystalline beams: The horizontal zigzag. Informal report

Description: The authors continue their investigation of {open_quotes}Crystalline Beams{close_quotes} in the ground state. In this paper they study the possibility of storing an intense beam of charged particles in a storage ring where the particles acquire a horizontal zigzag configuration. They define the equilibrium configuration, and examine the confinement and stability conditions. The problem of {open_quotes}shear{close_quotes} between particles circulating side by side caused by the curvature of the … more
Date: May 8, 1994
Creator: Haffmans, A. F.; Maletic, D. & Ruggiero, A. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Optimizing the length of the stores and related effects

Description: This memo is an attempt to create an accurate analytical model for the luminosity obtained in the Fermilab Tevatron during collider operation. Other people, in particular Alan Hahn and, aledgedly, Vinod Bharadwaj and Gerry Dugan, have addressed this topic and predicted an optimum store duration. The approach taken here is slightly different from Hahn`s, in particular, analytic forms for the model are written down and the optima are found directly, through differentiation. Also, specifying the p… more
Date: October 7, 1994
Creator: McCrory, E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Coupling correction using closed orbit measurements

Description: The authors describe a coupling correction scheme they have developed and used to successfully reduce the vertical emittance of the NSLS X-Ray ring by a factor of 6 to below 2 A. This gives a vertical to horizontal emittance ratio of less than 0.2%. They find the strengths of 17 skew quadrupoles to simultaneously minimize the vertical dispersion and the coupling. As a measure of coupling they utilize the shift in vertical closed orbit resulting from a change in strength of a horizontal steering… more
Date: February 18, 1994
Creator: Safranek, J. & Krinsky, S.
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Partner: UNT Libraries Government Documents Department
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Acceleration theorems

Description: Electromagnetic fields can be separated into near and far components. Near fields are extensions of static fields. They do not radiate, and they fall off more rapidly from a source than far fields. Near fields can accelerate particles, but the ratio of acceleration to source fields at a distance R, is always less than R/{lambda} or 1, whichever is smaller. Far fields can be represented as sums of plane parallel, transversely polarized waves that travel at the velocity of light. A single such wa… more
Date: June 1, 1994
Creator: Palmer, R.
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Partner: UNT Libraries Government Documents Department
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Decoherence and recoherence of beam in phase space

Description: By use of the particle distribution in phase space, a new approach is introduced to study the decoherence and recoherence of a kicked beam when betatron tunes are far from any resonance. With this method, the decoherence and the recoherence of a beam can be analyzed easily in both 2-dimensional and 4-dimensional cases with any form of the tune spread. The decoherence of a beam initially trapped in a resonance island was also studied. Due to the tune modulation, the separatrix of island develops… more
Date: June 1, 1993
Creator: Jicong, Shi & Shoroku, Ohnuma
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Partner: UNT Libraries Government Documents Department
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Broadband impedance of the B factory

Description: The broadband impedance is described phenomenologically by expansion over {radical}{omega}. It is shown that different terms of the expansion correctly describe particular impedance-generating elements. The broadband impedance and the wake function of the B factory are reconstructed with numeric code TBCI. The losses at the interaction region due to excitation of the higher order modes (HOM) are estimated.
Date: April 1, 1993
Creator: Heifets, S.
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Partner: UNT Libraries Government Documents Department
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Beam-beam interaction working group summary

Description: The limit in hadron colliders is understood phenomenologically. The beam-beam interaction produces nonlinear resonances and makes the transverse tunes amplitude dependent. Tune spreads result from the latter, and as long as these tune spreads do not overlap low order resonances, the lifetime and performance is acceptable. Experience is that tenth and sometimes twelfth order resonances must be avoided, and the hadron collider limit corresponds roughly to the space available between resonances of… more
Date: March 1, 1995
Creator: Siemann, R. H.
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Partner: UNT Libraries Government Documents Department
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Bench-marking beam-beam simulations using coherent quadrupole effects

Description: Computer simulations are used extensively in the study of the beam-beam interaction. The proliferation of such codes raises the important question of their reliability, and motivates the development of a dependable set of bench-marks. We argue that rather than detailed quantitative comparisons, the ability of different codes to predict the same qualitative physics should be used as a criterion for such bench-marks. We use the striking phenomenon of coherent quadrupole oscillations as one such b… more
Date: June 1, 1992
Creator: Krishnagopal, S. & Chin, Y. H.
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Partner: UNT Libraries Government Documents Department
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A contemporary guide to beam dynamics

Description: A methodological discussion is given for single particle beam dynamics in circular machines. The discussions are introductory, but (or, even therefore) we avoid to rely on too much simplified concepts. We treat things from a very general and fundamental point of view, because this is the easiest and rightest way to teach how to simulate particle motion and how to analyze its results. We give some principles of particle tracking free from theoretical prejudices. We also introduce some transparen… more
Date: September 1, 1992
Creator: Forest, E. & Hirata, Kohji
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Issues in multi-bunch emittance preservation in the NLC

Description: In the linac of the SLAC NLC design 1 nC bunches are accelerated in trains 90 bunches long with an interbunch spacing of 42 cm. In this multi-bunch design one important problem that needs to be controlled is the multi-bunch beam break-up instability. One method of controlling this instability is by detuning the transverse modes of the accelerator cavities. This is accomplished by varying the cell dimensions as one proceeds down the structure in such a way that the transverse modes are detuned, … more
Date: July 1, 1994
Creator: Bane, K. L. F.; Adolphsen, C.; Kubo, K. & Thompson, K. A.
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Partner: UNT Libraries Government Documents Department
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