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    

Teytelman, D.

Paper Title Page
TUPCH200 Amplitude Linearizers for PEP-II 1.2 MW Klystrons and LLRF Systems 1480
 
  • D. Van Winkle, J. Browne, J.D. Fox, T. Mastorides, C.H. Rivetta, D. Teytelman
    SLAC, Menlo Park, California
  
  The PEP-II B-factory has aggressive current increases planned for luminosity through 2008. At 2.2 A (HER) on 4 A (LER) currents, longitudinal growth rates will exceed the damping rates achievable in the existing low level RF and longitudinal low mode feedback systems. Klystron gain non-linearity has been shown to be a key contributor to these increased growth rates through time domain non-linear modeling and machine measurements. Four prototype klystron amplitude modulation linearizers have been developed to explore improved linearity in the LLRF system. The linearizers operate at 475 MHz with 15 dB dynamic range and 1 MHz linear control bandwidth. Results from lab measurements and high current beam tests are presented. Future development progress and production designs are detailed.  
MOPLS028 DAFNE Status Report 604
 
  • A. Gallo, D. Alesini, M.E. Biagini, C. Biscari, R. Boni, M. Boscolo, B. Buonomo, A. Clozza, G.O. Delle Monache, E. Di Pasquale, G. Di Pirro, A. Drago, A. Ghigo, S. Guiducci, M. Incurvati, P. Iorio, C. Ligi, F. Marcellini, C. Marchetti, G. Mazzitelli, C. Milardi, L. Pellegrino, M.A. Preger, L. Quintieri, R. Ricci, U. Rotundo, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, S. Tomassini, C. Vaccarezza, M. Vescovi, M. Zobov
    INFN/LNF, Frascati (Roma)
  • G. Benedetti
    CELLS, Bellaterra (Cerdanyola del Vallès)
  • L. Falbo
    INFN-Pisa, Pisa
  • J.D. Fox, P. Raimondi, D. Teytelman
    SLAC, Menlo Park, California
  • E. Levichev, S.A. Nikitin, P.A. Piminov, D.N. Shatilov
    BINP SB RAS, Novosibirsk
  
  The operation of DAFNE, the 1.02 GeV c.m. e+e- collider of the Frascati National Laboratory with the KLOE detector, started in April 2004 has been concluded at the end of March 2006 with a total delivered luminosity of 2 fb-1 on the peak of the Phi resonance, 0.2 fb-1 off peak and a high statistics scan of the resonance. The best performances of the collider during this run have been a peak luminosity of 1.5 1032 cm-2s-1 and a daily delivered luminosity of 10 pb-1. The KLOE detector has been removed from one of the two interaction regions and its low beta section substituted with a standard magnetic structure, allowing for an easy vertical separation of the beams, while the FINUDA detector has been moved onto the second interaction point. Several improvements on the rings have also been implemented and are described together with the results of machine studies aimed at improving the collider efficiency and testing new operating conditions.  
MOPLS045 Achieving a Luminosity of 1034/cm2/s in the PEP-II B-factory 643
 
  • J. Seeman, J. Browne, Y. Cai, W.S. Colocho, F.-J. Decker, M.H. Donald, S. Ecklund, R.A. Erickson, A.S. Fisher, J.D. Fox, S.A. Heifets, R.H. Iverson, A. Kulikov, A. Novokhatski, V. Pacak, M.T.F. Pivi, C.H. Rivetta, M.C. Ross, P. Schuh, K.G. Sonnad, M. Stanek, M.K. Sullivan, P. Tenenbaum, D. Teytelman, J.L. Turner, D. Van Winkle, M. Weaver, U. Wienands, W. Wittmer, M. Woodley, Y.T. Yan, G. Yocky
    SLAC, Menlo Park, California
  • M.E. Biagini
    INFN/LNF, Frascati (Roma)
  • W. Kozanecki
    CEA, Gif-sur-Yvette
  
  For the PEP-II Operation Staff: PEP-II is an asymmetric e+e- collider operating at the Upsilon 4S and has recently set several performance records. The luminosity has exceeded 1x1034/cm2/s and has delivered an integrated luminosity of 728/pb in one day. PEP-II operates in continuous injection mode for both beams, boosting the integrated luminosity. The peak positron current has reached 2.94 A and 1.74 A of electrons in 1732 bunches. The total integrated luminosity since turn on in 1999 has reached over 333/fb. This paper reviews the present performance issues of PEP-II and also the planned increase of luminosity in the near future to over 2 x 1034/cm2/s. Upgrade details and plans are discussed.  
MOPLS049 Anomalous High Radiation Beam Aborts in the PEP-II B-factory 652
 
  • M.K. Sullivan, Y. Cai, S. DeBarger, F.-J. Decker, S. Ecklund, A.S. Fisher, S.M. Gierman, S.A. Heifets, R.H. Iverson, A. Kulikov, N. Kurita, S.J. Metcalfe, A. Novokhatski, J. Seeman, K.G. Sonnad, D. Teytelman, J.L. Turner, U. Wienands, D. Wright, Y.T. Yan, G. Yocky
    SLAC, Menlo Park, California
  
  The PEP-II B-factory at SLAC has recently experienced unexpected beam losses due to anomalously high radiation levels at the BaBar detector. The problem was finally traced to the occurrence of very high pressure (>100 nTorr) spikes that have a very short duration (few seconds). We describe the events and show analysis predicting where in the vacuum system the events originated and describe what was discovered in the vacuum system.  
MOPLS051 Tracking Down a Fast Instability in the PEP-II LER 658
 
  • U. Wienands, R. Akre, S.C. Curry, S. DeBarger, F.-J. Decker, S. Ecklund, A.S. Fisher, S.A. Heifets, A. Krasnykh, A. Kulikov, A. Novokhatski, J. Seeman, M.K. Sullivan, D. Teytelman, D. Van Winkle, G. Yocky
    SLAC, Menlo Park, California
  
  During Run 5, the beam in the PEP-II Low Energy Ring (LER) became affected by a predominantly vertical instability with very fast growth rate of 10…60/ms - much faster than seen in controlled grow-damp experiments - and varying threshold. The coherent amplitude of the oscillation was limited to approx. 1 mm pk-pk or less and would damp down over a few tens of turns; however, beam loss set in even as the measured amplitude damped, causing a beam abort. This led to the conclusion that the beam was actually blowing up. The presence of a 2 nu_s line in the spectrum suggested a possible head-tail nature of the instability, although chromaticity was not effective in raising the threshold. In this paper we will describe the measurements and data taken to isolate and locate the cause of the instability and, eventually, the discovery and fix of the root cause.  
THPCH101 Modeling and Simulation of Longitudinal Dynamics for LER-HER PEP II Rings 3032
 
  • C.H. Rivetta, J.D. Fox, T. Mastorides, D. Teytelman, D. Van Winkle
    SLAC, Menlo Park, California
  
  A time domain dynamic model and simulation tool for beam-cavity interactions in LER and HER rings at PEP II is presented. The motivation for this tool is to explore the stability margins and performance limits of PEP II LLRF systems at higher currents and upgraded RF configurations. It also serves as test bed for new control algorithms and to define the ultimate limits of the architecture. The tool captures the dynamical behavior of the beam-cavity interaction based on a reduced model. It includes nonlinear elements in the klystron and signal processing. The beam current is represented by macro-bunches. Multiple RF stations in the ring are represented via one or two single macro-cavities. Each macro-cavity captures the overall behavior of all the 2 or 4 cavity RF stations. This allows modeling the longitudinal impedance control loops interacting with the longitudinal beam model. Validation of simulation tool is in progress by comparing the measured growth rates for both LER and HER rings with simulation results. The simulated behavior of both machines at high currents are presented comparing different control strategies and the effect of non-linear klystrons and the linearizer.  
THPCH103 Design and Testing of Gproto Bunch-by-bunch Signal Processor 3038
 
  • D. Teytelman, R. Akre, J.D. Fox, A. Krasnykh, C.H. Rivetta, D. Van Winkle
    SLAC, Menlo Park, California
  • A. Drago
    INFN/LNF, Frascati (Roma)
  • J.W. Flanagan, T. Naito, M. Tobiyama
    KEK, Ibaraki
  
  A prototype programmable bunch-by-bunch signal acquisition and processing channel with multiple applications in storage rings has been developed at SLAC. The processing channel supports up to 5120 bunches with bunch spacings as close as 1.9 ns. The prototype has been tested and operated in five storage rings: SPEAR-3, DAFNE, PEP-II, KEKB, and ATF damping ring. The testing included such applications as transverse and longitudinal coupled-bunch instability control, bunch-by-bunch luminosity monitoring, and injection diagnostic. In this contribution the prototype design will be described and its operation will be illustrated with the data measured at the abovementioned accelerators.