THE GENERATION OF 400 MW RF PULSES AT X-BAND USING RESONANT DELAY LINES
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THE GENERATION OF 400 MW RF PULSES AT X-BAND USING RESONANT DELAY LINES Sami G. Tantawi , Roderick J. Loewen, Christopher D. Nantista, and Arnold E. Vlieks Stanford Linear Accelerator Center, Stanford University, P.O. Box 4349, MS 26, Stanford CA94309 * Also with the Communications and Electronics Department, Cairo University, Giza, Egypt
description
THE GENERATION OF 400 MW RF PULSES AT X-BAND USING RESONANT DELAY LINES. Sami G. Tantawi , Roderick J. Loewen, Christopher D. Nantista, and Arnold E. Vlieks Stanford Linear Accelerator Center, Stanford University, P.O. Box 4349, MS 26, Stanford CA94309 - PowerPoint PPT Presentation
Transcript of THE GENERATION OF 400 MW RF PULSES AT X-BAND USING RESONANT DELAY LINES
THE GENERATION OF 400 MW RF PULSES AT X-BAND USING RESONANT
DELAY LINES
Sami G. Tantawi, Roderick J. Loewen, Christopher D. Nantista, and Arnold E. Vlieks Stanford Linear Accelerator Center, Stanford University,
P.O. Box 4349, MS 26, Stanford CA94309*Also with the Communications and Electronics Department, Cairo
University, Giza, Egypt
• Out Line– Motivation– Theory of Resonant Delay Line Pulse
Compression System– System Implementation and Components– Low Power Measurements– High Power System and Results
Motivation
• The Current Next Linear Collider design have accelerator structure sections that requires a 200 MW, 375 nS pulses at 11.424 GHz. The available power supplies are 75 MW klystrons which produces more than 1.5 S pulses. Hence, pulse compression is needed.
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p
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pGainPowerMaximum
Input
Output
Wrap-around Mode Converter
H-Plane Over-moded Hybrid
Iris
Delay Lines
Resonant Delay Line Pulse Compression System To separate the input signal from the reflected signal, one might use two delay lines fed by a 3 dB hybrid as shown in Fig. 4. The reflected signal from both lines can be made to add at the forth port of the hybrid. Fig. 4. shows the pulse-compression system. For delay lines, it uses two 41.6-meter long cylindrical copper waveguides, each is 12.065 cm in diameter and operating in the TE01 mode. In theory, these over-moded delay lines can form a storage cavity with a quality factor Q > 1x106. A shorting plate, whose axial position is controllable to within ±4 µm by a stepper motor, terminates each of the delay lines. The input of the line is tapered down to a 4.737 cm diameter waveguide at which the TE02 mode is cut-off; hence, the circular irises which determine the coupling to the lines do not excite higher order modes provided that they are perfectly concentric with the waveguide axis.
The Wrap-Around Mode Converter. The physical model shown in the picture does not have the back wall shorting plate, this is done for illustration purposes only.
HFSS simulation results for the wrap around mode converter. The color shades represents the magnitude of the electrical field. a. is a cut plane through the slots, b is a cut plane in the circular guide 2.5 cm away from the slots.
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Frequency (GHz)
Port 1
Port 2
Port 3
Port 4
Height
Inductive posts
Port 1 Port 2
Port 3 Port 4
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Frequency (GHz)
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Pulse compressor inputPulse compressor output
Pow
er (
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Time (micro-seconds)
Conclusion• We have demonstrated an efficient pulse
compression system based on Resonant Delay Lines
• Several new over-moded rf components that have a very high efficiency have been presented
• The High power operation of the system yielded 150 ns, flat-top pulses of peak powers greater than 470 MW.
