USC, Los Angeles, California
UCLA, Los Angeles, California
SLAC, Menlo Park, California
*M. J. Hogan et al. Phys. Rev. Lett. 95, 054802, 2005.
CERN, Geneva
Osaka University, Osaka
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| 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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| WEOAPA02 | Optimum Frequency and Gradient for the CLIC Main Linac | 1867 |
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| A novel procedure for the optimization of the operating frequency, the accelerating gradient, and many other parameters of the CLIC main linac is presented. Based on the new accelerating structure design HDS (Hybrid Damped Structure), the optimization procedure takes into account both beam dynamics (BD) and RF constraints. BD constraints are related to emittance growth due to short- and long-range transverse wakefields. RF constraints are related to RF breakdown and pulsed surface heating limitations of the accelerating structure. Interpolation of beam and structure parameters in a wide range allows hundreds of millions of structures to be analyzed. Only those structures which satisfy BD and RF constraints are evaluated further in terms of ratio of luminosity to main linac input power, which is used as the figure of merit. The frequency and gradient have been varied in the range 12-30 GHz and 90-150 MV/m, respectively. It is shown that the optimum frequency varies in the range from 16 to 20 GHz depending on the accelerating gradient and that the optimum gradient is below 100 MV/m and that changing frequency and gradient can double the luminosity for the same main linac input power. | ||
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| WEOAPA03 | MICE Overview - Physics Goals and Prospects | 1870 |
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| Ionization cooling, a technique in which muon beam is passed through a series of absorbers and followed by RF-acceleration, is a proposed method for cooling muon beam, i.e., phase-space reduction. The international Muon Ionisation Cooling Experiment (MICE), which will construct and operate a realistic cooling channel and measure the beam cooling performance, is the first essential step towardsrealization of nutrino factories and eventually muon colliders based on intense muon sources. The MICE have got approved to be constructedin Rutherford Appleton Laboratory (RAL) and the fist beam commissioning is scheduled in 2007. The physics goal and future prospects of the MICE together with the beamline and the instruments which is now being built will be described. | ||
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