A PPM-focused klystron at X-band with a traveling-wave output structure
- Stanford Linear Accelerator Center, P.O. Box 4349, Stanford, California 94309 (United States)
We have developed algorithms for designing disk-loaded traveling-wave output structures for X-band klystrons to be used in the SLAC NLC. We use either a four- or five-cell structure in a {pi}/2 mode. The disk radii are tapered to produce an approximately constant gradient. The matching calculation is not performed on the tapered structure, but rather on a coupler whose input and output cells are the same as the final cell of the tapered structure, and whose interior cells are the same as the penultimate cell in the tapered structure. 2-D calculations using CONDOR model the waveguide as a radial transmission line of adjustable impedance. 3-D calculations with MAFIA model the actual rectangular waveguide and coupling slot. A good match is obtained by adjusting the impedance of the final cell. In 3-D, this requires varying both the radius of the cell and the width of the aperture. When the output cell with the best match is inserted in the tapered structure, we obtain excellent cold-test agreement between the 2-D and 3-D models. We use hot-test simulations with CONDOR to design a structure with maximum efficiency and minimum surface fields. We have designed circuits at 11.424 Ghz for different perveances. At 440 kV, microperveance 1.2, we calculated 81 MW, 53 percent efficiency, with peak surface field 76 MV/m. A microperveance 0.6 design was done using a PPM stack for focusing. At 470 kV, 193 amps, we calculated 58.7 MW, 64.7 percent efficiency, peak surface field 62.3 MV/m. At 500 kV, 212 amps, we calculated 67.1 MW, 63.3 percent efficiency, peak surface field 66.0 MV/m. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.
- Research Organization:
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- DOE Contract Number:
- AC03-76SF00515
- OSTI ID:
- 115768
- Report Number(s):
- CONF-9410218-; ISSN 0094-243X; TRN: 95:022547
- Journal Information:
- AIP Conference Proceedings, Vol. 337, Issue 1; Conference: Pulsed radio frequency sources for linear colliders, Long Island, NY (United States), 2-7 Oct 1994; Other Information: PBD: 5 Jul 1995
- Country of Publication:
- United States
- Language:
- English
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