| Paper |
Title |
Other Keywords |
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| MOPLT073 |
Picosecond High Voltage Switching for Pulsed DC Acceleration
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laser, acceleration, electron, plasma |
722 |
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- J. Hendriks, G.J.H. Brussaard
TUE, Eindhoven
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Laser wakefield acceleration promises the production of high energy electrons from table-top accelerators. External injection of a (low energy) electron bunch into a laser wakefield requires acceleration gradients of the order GV/m. In principle DC acceleration can achieve GV/m acceleration gradients. If high voltage pulses of the order MV can be switched with picosecond precision, the performance of such an accelerator would be greatly enhanced and even multistage DC acceleration would become feasible. Presently risetime and jitter of high voltage pulses in high voltage laser triggered spark gaps are limited to the nanosecond regime by the initial stochastic breakdown process in the gap. A way to overcome this limitation is to create a line focus between the electrodes with an intensity above 1018 W/m2 using a high power femtosecond Ti:Sapphire laser. Because of the instantaneous ionization and high degree of ionization in the plasma channel, picosecond switching precision can be achieved and jitter is reduced significantly. A spark gap test setup with 3 mm interelectrode distance has been build and the first measurements have been done. Femtosecond diagnostics for characterization of the laser induced plasma and electro-optic diagnostics for the high voltage pulse have been developed.
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| WEPKF076 |
Solid-state Marx Bank Modulator for the Next Linear Collider
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klystron, cathode, linear-collider, collider |
1783 |
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- M.A. Kempkes, F.O. Arntz, J.A. Casey, M.P.J. Gaudreau
Diversified Technologies, Inc., Bedford
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The Next Generation Linear Collider (NLC) will require hundreds to thousands of pulse modulators to service more than 3300 klystrons. DTI recently investigated the use of a solid-state Marx switch topology for the NLC, and has transitioned this work into the development of a full-scale, 500 V solid state Marx system. Combined with recent advances in semiconductor technology and packaging, these efforts have moved the performance of the Marx pulser far ahead of early estimates. The Marx pulser eliminates the pulse transformer, which is associated with significant loss of performance and a 15-20% penalty in the efficiency of a conventional modulator. The increase in efficiency attributable to the Marx topology can account for over $100M in power cost savings over ten years of NLC operation, an amount comparable to the acquisition costs of the pulsed power systems. In this paper, DTI will discuss the design and development of the Marx Bank modulator. Its performance scales to 125 ns risetime (10-90%) for either a 500 kV, 265 A pulse (for one klystron), or a 500 kV, 530 A pulse (for two klystrons). The use of a unique, common mode inductive charging system allows transfer of filament power without separate isolation transformers.
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| WEPKF087 |
SNS Extraction Fast Kicker Pulsed Power System
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kicker, extraction, impedance, vacuum |
1810 |
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- W. Zhang, H. Hahn, J.-L. Mi, C. Pai, J. Sandberg, Y. Tan, N. Tsoupas, J. Tuozzolo, D.S. Warburton, J. Wei
BNL, Upton, Long Island, New York
- R. Cutler, K. Rust
ORNL/SNS, Oak Ridge, Tennessee
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The Spallation Neutron Source (SNS) is a next generation high intensity beam facility. Its Accumulator Ring Extraction Fast Kicker System is a very high peak power, high average power, high precision pulse-waveform, ultra-low beam impedance, and high repetition rated pulsed power system. It has been successfully design and developed at Brookhaven National Laboratory. This system will consist of fourteen identical high voltage modulators and fourteen extraction magnet sections located inside of the SNS accumulator ring. The overall system output will reach multiple GW peak power with 60 Pulse-per-second repetition rates. The techniques of reducing impedance, improving rise time, and minimizing ripples will be discussed. The lifetime considerations, issues of the system design, development and construction are presented in this paper.
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