2008 IEEE Antennas and Propagation Society International Symposium, 2008
Parametric variations of the TBH antenna over a perfect ground plane were studied to gain insight... more Parametric variations of the TBH antenna over a perfect ground plane were studied to gain insight to the roles played by the key parameters in affecting antenna characteristics. Results of simulations were compared to approximate models based on the superposition of radiation from small loops and monopole. Maximum antenna bandwidth was achieved for a helical conductor width equal to frac12 the helical pitch and a helical core diameter approximately equal to the distance from the center of the helix to the ground plane. Bandwidth is reduced by pacing the helix on a high permittivity core material. Increasing the loss tangent of the core can improve bandwidth but at the expense of antenna efficiency. The directive gain and radiation resistance given by superposition of elementary radiating components are found to be in close agreement with the simulation results.
In this paper, we present updated results on power extraction testing of a 7.8 GHz dielectric loa... more In this paper, we present updated results on power extraction testing of a 7.8 GHz dielectric loaded waveguide power extractor using both high charge single bunches and bunch trains. We have generated a 1.7 ns radio frequency (rf) pulse with 30 MW of power with a single 66 nC electron bunch. Then we have generated a pulse train of electron beam for rf generation of 10 ns and 22 ns rf pulses.
Physical Review Special Topics - Accelerators and Beams, 2008
Dielectric-loaded power extraction is a method for the generation of high-power radio frequency (... more Dielectric-loaded power extraction is a method for the generation of high-power radio frequency (rf) waves under development for future particle accelerators. In this method, a high-charge electron beam drives a wakefield in a dielectric-loaded waveguide (the decelerator) and an rf output coupler extracts the rf power into an external waveguide. We report on the experimental demonstration of a 7.8 GHz dielectricloaded power extractor at the Argonne Wakefield Accelerator facility. We have generated more than 30 MW of rf power with a pulse length of approximately 1.7 ns by passing a single 66 nC electron bunch through the power extractor. We have also used a train of 4 electron bunches to show a clear signature of field superposition. Test results are in good agreement with predictions.
We report on the design and beam tests of a 7.8GHz power extractor recently conducted at the Argo... more We report on the design and beam tests of a 7.8GHz power extractor recently conducted at the Argonne Wakefield Accelerator (AWA) facility. Wakefields are excited when an electron beam travels through a dielectric loaded waveguide, and the generated RF power is subsequently extracted with a properly designed RF coupler. The experiment shows that 30MW of output power is excited by a 66nC single electron bunch. Field superposition is also clearly demonstrated with a train of 4 electron bunches. Tests results are in good agreement with predictions.
2008 IEEE Antennas and Propagation Society International Symposium, 2008
Parametric variations of the TBH antenna over a perfect ground plane were studied to gain insight... more Parametric variations of the TBH antenna over a perfect ground plane were studied to gain insight to the roles played by the key parameters in affecting antenna characteristics. Results of simulations were compared to approximate models based on the superposition of radiation from small loops and monopole. Maximum antenna bandwidth was achieved for a helical conductor width equal to frac12 the helical pitch and a helical core diameter approximately equal to the distance from the center of the helix to the ground plane. Bandwidth is reduced by pacing the helix on a high permittivity core material. Increasing the loss tangent of the core can improve bandwidth but at the expense of antenna efficiency. The directive gain and radiation resistance given by superposition of elementary radiating components are found to be in close agreement with the simulation results.
In this paper, we present updated results on power extraction testing of a 7.8 GHz dielectric loa... more In this paper, we present updated results on power extraction testing of a 7.8 GHz dielectric loaded waveguide power extractor using both high charge single bunches and bunch trains. We have generated a 1.7 ns radio frequency (rf) pulse with 30 MW of power with a single 66 nC electron bunch. Then we have generated a pulse train of electron beam for rf generation of 10 ns and 22 ns rf pulses.
Physical Review Special Topics - Accelerators and Beams, 2008
Dielectric-loaded power extraction is a method for the generation of high-power radio frequency (... more Dielectric-loaded power extraction is a method for the generation of high-power radio frequency (rf) waves under development for future particle accelerators. In this method, a high-charge electron beam drives a wakefield in a dielectric-loaded waveguide (the decelerator) and an rf output coupler extracts the rf power into an external waveguide. We report on the experimental demonstration of a 7.8 GHz dielectricloaded power extractor at the Argonne Wakefield Accelerator facility. We have generated more than 30 MW of rf power with a pulse length of approximately 1.7 ns by passing a single 66 nC electron bunch through the power extractor. We have also used a train of 4 electron bunches to show a clear signature of field superposition. Test results are in good agreement with predictions.
We report on the design and beam tests of a 7.8GHz power extractor recently conducted at the Argo... more We report on the design and beam tests of a 7.8GHz power extractor recently conducted at the Argonne Wakefield Accelerator (AWA) facility. Wakefields are excited when an electron beam travels through a dielectric loaded waveguide, and the generated RF power is subsequently extracted with a properly designed RF coupler. The experiment shows that 30MW of output power is excited by a 66nC single electron bunch. Field superposition is also clearly demonstrated with a train of 4 electron bunches. Tests results are in good agreement with predictions.
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