Paper | Title | Page |
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MOPLS049 | Anomalous High Radiation Beam Aborts in the PEP-II B-factory | 652 |
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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. | ||
MOPLS045 | Achieving a Luminosity of 1034/cm2/s in the PEP-II B-factory | 643 |
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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. | ||
MOPLS067 | Test Beam Studies at SLAC's End Station A, for the International Linear Collider | 700 |
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The SLAC Linac can deliver to End Station A a high-energy test beam with similar beam parameters as for the International Linear Collider for bunch charge, bunch length and bunch energy spread. ESA beam tests run parasitically with PEP-II with single damped bunches at 10Hz, beam energy of 28.5 GeV and bunch charge of (1.5-2.0)·1010 electrons. A 5-day commissioning run was performed in January 2006, followed by a 2-week run in April. We describe the beamline configuration and beam setup for these runs, and give an overview of the tests being carried out. These tests include studies of collimator wakefields, prototype energy spectrometers, prototype beam position monitors for the ILC Linac, and characterization of beam-induced electro-magnetic interference along the ESA beamline. | ||
WEOAPA01 | Demonstration of Energy Gain Larger than 10GeV in a Plasma Wakefield Accelerator | 0 |
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We have recently demonstrating the excitation of accelerating gradients as large as 30 GV/m* using the ultra-short, 28.5 GeV electron bunches now available at the Stanford Linear Accelerator Center. As a result, the electrons in the back of the bunch gained about 3 GeV over the 10 cm-long plasma with a density of ?2.5x1017 e /cm-3. In recent experiments, energy gains in excess of 10 GeV, by far the largest in any plasma accelerators, have been measured over a plasma length of ?30 cm. Moreover, systematic measurements show the scaling of the energy gain with plasma length and density, and show the reproduceability and the stability of the acceleration process. These are key steps toward the application of beam-driven plasma accelerators or plasma wakefield accelerators (PWFA) to doubling the enregy of a future linear collider without doubling its length. We are preparing for experiments to be performed in February-March 2006 aiming at doubling the energy of the 28.5 GeV beam over a plasma length of less than one meter, a distance two thousand times shorter than the accelerator that created the incoming beam. The latest experimental results will be presented.
*M. J. Hogan et al. Phys. Rev. Lett. 95, 054802, 2005. |
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