Seeman, J.

Paper	Title	Page
MOPP064	Secondary Electron Yield Measurements and Groove Chambers Update Tests in the PEP-II Beam Line	691
	M. T.F. Pivi, F. King, R. E. Kirby, T. W. Markiewicz, T. O. Raubenheimer, J. Seeman, L. Wang SLAC, Menlo Park, California
	In the Low Energy Ring (LER) of the PEP-II accelerator, we have installed vacuum chambers with rectangular grooves in straight sections to test this possible mitigation technique for the electron cloud effect in the positron damping ring (DR) of the future Linear Colliders such as ILC and CLIC. We have also installed chambers to monitor the secondary electron yield (SEY) of TiN, TiZrV (NEG) and technical accelerator materials under the effect of electron and photon conditioning in situ. Furthermore, we have also installed test chambers in a new 4-magnet chicane. We describe the ongoing R&D effort to mitigate the electron cloud effect in the ILC damping ring, the chambers installation in the PEP-II and latest results.
TUXG01	Last Year of PEP-II B-Factory Operation	946
	J. Seeman SLAC, Menlo Park, California
	The PEP II B-Factory at SLAC has been in operation for a decade, delivering luminosity to the BABAR experiment. The design luminosity was successfully reached after one year of operation and since then it has surpassed over four times design at 1.2 x 1034 cm-2sec-1. History of main achievements, high current operation issues, and lessons for the future factories will be presented.
	Slides
TUPP053	Radiolocation of a HOM Source in the PEP-II Rings	1664
	A. Novokhatski, J. Seeman, M. K. Sullivan SLAC, Menlo Park, California
	A signal from the antenna situated in the LER (Low Energy Ring) helped to find a broken shielded bellows in the HER (High Energy Ring) during a single HER bunch operation.
TUPP054	A Model of an Electrical Discharge in the Flange Contacts with Omega Seals at High Currents in PEP-II	1667
	A. Novokhatski, J. Seeman, M. K. Sullivan SLAC, Menlo Park, California
	During operation with high currents at HER (High Energy Ring), high temperature elevation was found at almost every location of the vacuum chamber flange contacts. Omega RF seals were strongly damaged or even evaporated by sparks and electrical discharge. We suggest a physical model, which may explain this effect.
WEPP039	Design of a 1036 cm-2 s-1 Super-B Factory	2605
	J. Seeman, K. J. Bertsche, A. Novokhatski, M. K. Sullivan, U. Wienands, W. Wittmer SLAC, Menlo Park, California S. Bettoni CERN, Geneva M. E. Biagini, R. Boni, M. Boscolo, T. Demma, A. Drago, S. Guiducci, P. Raimondi, S. Tomassini, M. Zobov INFN/LNF, Frascati (Roma) A. Bogomyagkov, I. Koop, E. B. Levichev, S. A. Nikitin, P. A. Piminov, D. N. Shatilov BINP SB RAS, Novosibirsk G. Marchiori INFN-Pisa, Pisa E. Paoloni University of Pisa and INFN, Pisa
	Submitted for the High Luminosity Study Group for an Asymmetric Super-B-Factory: Parameters are being studied for a high luminosity e+e- collider operating at the Upsilon 4S that would deliver a luminosity of 1 to 2 x 1036/cm2/s. This collider would use a novel combination of linear collider and storage ring techniques. In this scheme an electron beam and a positron beam are stored in low-emittance damping rings similar to those designed for a Linear Collider (LC) or the next generation light source. A LC style interaction region is included in the ring to produce sub-millimeter vertical beta functions at the collision point. A large crossing angle (±25 mrad) is used at the collision point to allow beam separation. A crab-waist scheme is used to reduce the hourglass effect and restore peak luminosity. Beam currents of about 1.8 A in 1400 bunches can produce a luminosity of 1036/cm2/s with upgrade possibilities. Design parameters and beam dynamics effects are discussed.
WEPP042	An Improved Design for a SuperB Interaction Region	2614
	M. K. Sullivan, J. Seeman, U. Wienands SLAC, Menlo Park, California S. Bettoni CERN, Geneva M. E. Biagini, P. Raimondi INFN/LNF, Frascati (Roma) E. Paoloni University of Pisa and INFN, Pisa
	We present an improved design for a SuperB interaction region. The new design attempts to minimize the bending of the two colliding beams which results from shared magnetic elements near the Interaction Point (IP). The total crossing angle at the IP is increased from 34 mrad to 50 mrad and the distance from the IP to the first quadrupole is increased. Although the two beams still travel through this shared magnet, these changes allow for a new a new magnetic field design with a septum which gives the magnet two magnetic centers. This greatly reduces the beam bending from this shared quadrupole and thereby reduces the radiative bhabha background for the detector as well as any beam emittance growth from the bending. We decribe the new design for the interaction region.
MOPP063	A New Chicane Experiment in PEP-II to Test Mitigations of the Electron Cloud Effect for Linear Colliders	688
	M. T.F. Pivi, D. Arnett, F. D. Cooper, D. Kharakh, F. King, R. E. Kirby, B. Kuekan, J. J. Lipari, M. Munro, J. S.T. Ng, J. Olszewski, T. O. Raubenheimer, J. Seeman, B. Smith, C. M. Spencer, L. Wang, W. Wittmer SLAC, Menlo Park, California C. M. Celata, M. A. Furman LBNL, Berkeley, California
	Beam instability caused by the electron cloud has been observed in positron and proton storage rings and it is expected to be a limiting factor in the performance of the positron Damping Ring (DR) of future Linear Colliders such as ILC and CLIC. Possible remedies for the electron cloud effect include thin-film coatings, surface conditioning, antechamber, clearing electrodes, and chamber with grooves or slots. The effect is expected to be particularly severe in magnetic field regions. To test this and possible mitigation methods, we have installed a new 4-dipole chicane experiment in the PEP-II Low Energy Ring (LER). We have also installed test chambers in straight field free regions. The associated chamber consists of bare aluminum and TiN-coated inner surface sections. Each section is instrumented with arrays of readout electrodes and retarding grids. Installation of a grooved chamber is also planned. In this paper, we describe the ongoing R&D effort at SLAC to reduce the electron cloud effect in linear colliders. We present the design of the chicane, the chambers and diagnostics, as well as the experimental results obtained.
WEPC023	Ideas for a Future PEP Light Source	2031
	R. O. Hettel, K. L.F. Bane, L. D. Bentson, K. J. Bertsche, S. M. Brennan, Y. Cai, A. Chao, S. DeBarger, V. A. Dolgashev, X. Huang, Z. Huang, D. Kharakh, Y. Nosochkov, T. Rabedeau, J. A. Safranek, J. Seeman, J. Stohr, G. V. Stupakov, S. G. Tantawi, L. Wang, M.-H. Wang, U. Wienands SLAC, Menlo Park, California I. Lindau Stanford University, Stanford, Califormia C. Pellegrini UCLA, Los Angeles, California
	With the termination of operation of the PEP-II storage rings for high energy physics at hand, and with the migration of accelerator operation at SLAC in general to photon science applications, a study of the potential conversion of the PEP-II to a future light source has been initiated. With a circumference of 2.2 km and the capability for high current operation, it is clear that operating a converted ring at medium energy (3-6 GeV) could offer very low emittance and an average brightness of order 1022, limited primarily by the power handling capacity of photon beam line optical components. Higher brightness in the soft X-ray regime might be reached with partial lasing in long undulators if the emittance is sufficiently low, and high peak brightness could be reached with seeded FEL emission. Advanced pulsed rf technology might be used to generate short bunches and fast switched polarization in soft X-ray rf undulators. An overview of the preliminary findings of the PEP Light Source study group will be presented, including lattice, X-ray source and beam line options.
WEPP040	New Low Emittance Lattices for the SuperB Accelerator Project	2608
	M. E. Biagini, M. Boscolo, P. Raimondi, S. Tomassini, M. Zobov INFN/LNF, Frascati (Roma) S. Bettoni CERN, Geneva A. Bogomyagkov, I. Koop, E. B. Levichev, S. A. Nikitin, P. A. Piminov, D. N. Shatilov BINP SB RAS, Novosibirsk E. Paoloni University of Pisa and INFN, Pisa J. Seeman, M. K. Sullivan, U. Wienands, W. Wittmer SLAC, Menlo Park, California
	New low emittance lattices (1.6 nm at 7 GeV, 2.8 nm at 4 GeV) have been designed for the asymmetric SuperB accelerator aiming at a luminosity of 1036 cm-2 s-1. Main optics features are two alternating arc cells with different horizontal phase advance, in order to decrease beam emittance and allow at the same time for easy chromaticity correction in the arcs. Emittance can be further reduced by a factor of two for luminosity upgrade. New beam parameters have been chosen to fulfill the transparency conditions for 4x7 GeV beams, different from the asymmetric currents used in operating B-Factories. Beam polarization schemes have been studied and will be implemented in the lattice.