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Guo, W.

Paper Title Page
TUPMN093 A Kilohertz Picosecond X-Ray Pulse Generation Scheme 1133
  • W. Guo, M. Borland, K. C. Harkay, C.-X. Wang, B. X. Yang
    ANL, Argonne, Illinois
  The duration of the x-ray pulse generated at a synchrotron light source is typically tens of picoseconds. Shorter pulses are highly desired by the users. In electron storage rings, the vertical beam size is usually orders of magnitude less than the bunch length due to radiation damping; therefore, a shorter pulse can be obtained by slitting the vertically tilted bunch. Zholents proposed tilting the bunch using rf deflection. We found that tilted bunches can also be generated by a dipole magnet kick. A vertical tilt is developed after the kick in the presence of non-zero chromaticity. The tilt was successfully observed and a 4.2-ps pulse was obtained fom a 27-ps electron bunch at the Advanced Photon Source. Based on this principle we propose a short-pulse generation scheme that produces picosecond x-ray pulses at a repetition rate of 1~2 kHz, which can be used for pump-probe experiments. The tilt phenomenon can also be utilized for machine parameter measurement.  
TUPMS072 Longitudinal Beam Parameter Tolerances of NSLS II 1338
  • W. Guo, G. L. Carr, S. Krinsky, J. Rose
    BNL, Upton, Long Island, New York
  Funding: National Synchrotron Light Source II

A notable feature of the proposed National Synchrotron Light Source II is that the vertical emittance is close to the diffraction limit of 1 Angstrom. With such a small emittance, the brightness is strongly affected by the longitudinal parameters, such as the momentum spread. Various effects are discussed and tolerances on the longitudinal parameters will be given. The lower level RF feedback system will be designed based on these tolerances.

TUPMS073 Dispersion Tolerance Calculation for NSLS-II 1341
  • W. Guo, S. Krinsky, F. Lin
    BNL, Upton, Long Island, New York
  The approach for the proposed National Synchrotron Light Source II to reach small transverse emittances is to deploy damping wigglers. In the ideal lattice the dispersion is zero in the straight sections, therefore the damping wigglers supply only damping effect. In reality the residual dispersion can be generated by the lattice errors, trim dipoles, and the insertion devices. We will discuss dispersion introduced by different sources and calculate the tolerances. Possible correction schemes will also be presented.  
TUPMS074 Collective Effects in the NSLS-II Storage Ring 1344
  • S. Krinsky, J. Bengtsson, J. S. Berg, M. Blaskiewicz, A. Blednykh, W. Guo, N. Malitsky, C. Montag, B. Podobedov, J. Rose, N. A. Towne, L.-H. Yu
    BNL, Upton, Long Island, New York
  • F. Wang
    MIT, Middleton, Massachusetts
  Funding: This work was supported by Department of Energy contract DE-AC02-98CH10886.

A new high-brightness synchrotron light source (NSLS-II) is under design at BNL. The 3-GeV NSLS-II storage ring has a double-bend achromatic lattice with damping wigglers installed in zero-dispersion straights to reduce the emittance below 1nm. In this note, we present an overview of the impact of collective effects upon the performance of the storage ring. Subjects discussed include Touschek lifetime, intra-beam scattering, instability thresholds due to ring impedance, and use of a third-harmonic Landau cavity.

TUPMS083 Conceptual Design of the NSLS-II Injection System 1362
  • T. V. Shaftan, J. Beebe-Wang, J. Bengtsson, G. Ganetis, W. Guo, R. Heese, H.-C. Hseuh, E. D. Johnson, V. Litvinenko, A. U. Luccio, W. Meng, S. Ozaki, I. Pinayev, S. Pjerov, D. Raparia, J. Rose, S. Sharma, J. Skaritka, C. Stelmach, N. Tsoupas, D. Wang, L.-H. Yu
    BNL, Upton, Long Island, New York
  Funding: This work was supported by Department of Energy contract DE-AC02-98CH10886.

We present conceptual design of the NSLS-II injection system. The injection system consists of low-energy linac, booster and transport lines. We review the requirements on the injection system imposed by the storage ring design and means of meeting these requirements. We discuss main parameters and layout of the injection system components.

WEPMS091 Conceptual Design of the NSLS-II RF Systems 2550
  • J. Rose, A. Blednykh, W. Guo, P. Mortazavi, N. A. Towne
    BNL, Upton, Long Island, New York
  RF system requirements are derived from machine parameters and beam stability specifications. The conceptual design of the RF system for NSLS-II to meet these requirements is presented, consisting of 500 MHz superconducting main cavities, 1500 MHz SCRF harmonic cavities for bunch lengthening, and the RF power and cryogenic systems.