PAC07 - List of Authors (Wang, F.)

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Wang, F.

Paper	Title	Page
MOOAAB04	Quadruple-bend Achromatic Low Emittance Lattice Studies	86
	M.-H. Wang, H.-P. Chang, H. C. Chao, P. J. Chou, C.-C. Kuo NSRRC, Hsinchu S.-Y. Lee, F. Wang IUCF, Bloomington, Indiana
	A quadruple-bend-achromatic (QBA) cell, defined as a super cell made of two double-bend (DB) cells with different outer and inner dipole bend angles, is found to provide a factor of two in lowering the beam emittance of electron synchrotron light sources. The ratio of bending angles of the inner dipoles to that of the outer dipoles is numerically found to be about 1.5₁.6 for an optimal low beam emittance in the isomagnetic condition. The QBA lattice provides an advantage over the double-bend achromat or the double-bend non-achromat in performance by providing some zero dispersion straight-sections and a small natural beam emittance. A lattice with 12 QBA cells with a preliminary dynamic aperture study serves as an example. The effects of the different types of insertion devices (ID) on the emittance in dispersive long straight and non-dispersive long straight are also simulated and reported.
	Slides
WEPMS056	High Current, Large Aperture, Low HOM, Single Crystal Nb 2.85GHz Superconducting Cavity	2472
	Q. S. Shu, F. H. Lu, I. M. Phipps, J. L. Shi, J. T. Susta AMAC, Newport News, Virginia R. P. Redwine, D. Wang, F. Wang MIT, Middleton, Massachusetts
	Funding: Footnotes: The project was funded by the US Department of Energy under contract DE-FG02-05ER84346 There is an increasing demand for High beam Current, high Radio-Frequency (RF) power S-band cavities in existing and new accelerator projects to produce a very brilliant, broadband, teraherz coherent synchrotron radiation source (CRS). To achieve this goal, the RF cavities must be upgraded to a gap voltage of 1.5 MV in the limited space available in the machine with a high gradient superconducting cavity. At the present time there are no cavities and accessories designed to support the high beam currents of up to 100 mA and at the same time provide a high gap voltage at such a high S-band frequency. AMAC proposed a High Current, Large Aperture, Low HOM, Single Crystal Nb 2.85GHz Superconducting Cavity with high RF Power Coupler and HOM absorber device. Comprehensive simulation and optimization to determine the SRF cavity parameters to meet the requirements, provided two alternate designs for the RF input couplers, performed a detailed Higher Order Modes (HOM) analysis, and proposed an HOM absorber concept to dampen the modes exited in the cavity due to the high beam current and high bunch intensity.
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.
WEPMS041	Multipacting Simulations of TTF-III Coupler Components	2436
	L. Ge, C. Adolphsen, K. Ko, L. Lee, Z. Li, C.-K. Ng, G. L. Schussman, F. Wang SLAC, Menlo Park, California B. Rusnak LLNL, Livermore, California
	Funding: This work was supported by US DOE contract No. DE-AC02-76SF00515. This work was performed under the auspices of the US DOE by the University of California, LLNL under Contract No. W-7405-Eng-48. The TTF-III coupler adopted for the ILC baseline cavity design has shown a tendency to have long initial high power processing times. A possible cause for the long processing times is believed to be multipacting in various regions of the coupler. To understand performance limitations during high power processing, SLAC has built a flexible high-power coupler test stand. The plan is to test individual sections of the coupler, which includes the cold and warm coaxes, the cold and warm bellows, and the cold window, using the test stand to identify problematic regions. To provide insights for the high power test, detailed numerical simulations of multipacting for these sections will be performed using the 3D multipacting code Track3P. The simulation results will be compared with measurement data.
WEPMS017	High-Power Coupler Component Test Stand Status and Results	2367
	B. Rusnak LLNL, Livermore, California C. Adolphsen, G. B. Bowden, L. Ge, R. K. Jobe, Z. Li, B. D. McKee, C. D. Nantista, J. Tice, F. Wang SLAC, Menlo Park, California R. Swent Stanford University, Stanford, Califormia
	Funding: This work was performed under the auspices of the U. S. DOE by the University of California, LLNL under Contract No. W-7405-Eng-48. SLAC Work supported under Contract No. W-7405-Eng-48. Fundamental power couplers for superconducting accelerator applications like the ILC are complicated RF transmission line assemblies due to their having to simultaneously accommodate demanding RF power, cryogenic, and cleanliness constraints. When these couplers are RF conditioned, the observed response is an aggregate of all the parts of the coupler and the specific features that dominate the conditioning response are unknown. To better understand and characterize RF conditioning phenomena toward improving performance and reducing conditioning time, a high-power coupler component test stand has been built at SLAC. Operating at 1.3 GHz, this test stand was designed to measure the conditioning behavior of select components of the TTFIII coupler independently, including outer-conductor bellows, diameter changes, copper plating and surface preparations, and cold window geometries and coatings. A description of the test stand, the measurement approach, and a summary of the results obtained are presented.
FRPMS088	Intrabeam Scattering and Touschek Lifetime for the Optical Stochastic Cooling experiment at the MIT-Bates South Hall Ring	4279
	F. Wang, W. A. Franklin, C. Tschalaer, D. Wang, J. van der Laan MIT, Middleton, Massachusetts
	A proof-of-principal experiment of Optical Stochastic Cooling (OSC) at the MIT-Bates South Hall electron storage ring (SHR) has been proposed. To produce convincing cooling results, the ring will be run near 300 MeV. Beam emittances growth caused by Intrabeam scattering (IBS) is a major concern for the design of experiment. Touschek scattering imposes a dominant limit on beam lifetime. Evaluation of these effects is part of the design optimization process. Simulation analyses of cooling for a viable OSC experiment are presented.