| Paper | Title | Page |
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| MOPPH006 | Extracting Information from Smith-Purcell FEL Simulations | 45 |
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Simulations of Smith-Purcell radiation using 2D particle-in-cell codes have provided insight into the behavior of such devices, and have generally provided support to the viewpoint of the Vanderbilt University group*. However, if one is interested in Terahertz frequencies, the need for small meshes and short time intervals makes the calculations exceedingly long. In particular, the S-P correlation between frequency and angle is only valid at distances large compared to the grating size, and may not be apparent if the simulation area is too small. With the help of the multipole expansion, we show how simulation data obtained with a small area may be extended to an area of arbitrary size. This enables us to confirm the presence of coherent higher order S-P peaks at the appropriate angles.
* H. L. Andrews, C. H. Boulware, C. A. Brau, and J. D. Jarvis, Phys. Rev. ST Accel. Beams 8, 050703 (2005) |
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| MOPPH007 | Simulation of Smith-Purcell FELs at Terahertz Frequencies | 49 |
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Our previous work on the 2D simulation of a coherent Smith-Purcell FEL operating in the Terahertz domain is extended to a systematic study of the dependence on various parameters. The important question of the starting current reqired to produce coherent radiation is addressed, and our new results will be presented. As in our previous work we concentrate on two configurations, one similar to the Dartmouth S-P FEL*, with a low energy continuous beam, and the other similar to the MIT experiment which uses a pre-bunched 15 MeV beam**.
* A Bakhtyari, J. E. Walsh, and J. H. Brownell, Phys. Rev. Lett. E 65, 066503 (2002).** S. E. Korbly, A. S. Kesar, J. R. Sirigiri, and R. J. Temkin, Phys. Rev. Lett. 94, 054803 (2005) |