A field symmetrized dual feed 2 MeV RF gun for a 17 GHz electron linear accelerator
- Haimson Research Corporation, 3350 Scott Blvd., Building 60, Santa Clara, California 95054-3104 (United States)
An undesirable feature that contributes to beam emittance growth, and prevents the full potential of laser driven, short wavelength RF guns from being realized, is the presence of field asymmetries introduced by the input power coupling aperture in the sidewall of the cavity. Means of avoiding these field asymmetries in a three cavity RF gun structure, by feeding RF power into the middle cavity through diametrically opposed coupling apertures in the sidewalls of the cavity and by using a racetrack (rather than a cylindrical) shaped coupling cavity are described. An analysis of the {pi}-mode structure indicated that, although E-field balancing of the three-cell circuit was very sensitive to small departures from the resonant condition, the proposed microtuner mechanisms on each end cavity could readily correct for these resonant errors. Furthermore, unlike the use of tuning probes in the outer wall of the cavities, the slight axial deformation produced by the end wall microtuners enables the symmetrized field distributions to be conserved. Beam optics analyses indicate that a peak E-field of 200 MV/m and an energy gain of 2 MeV can be achieved with this 17 GHz RF gun using a peak input power of less than 3 MW. The design parameters of the three cavity structure are discussed: the results of beam optics studies and the racetrack coupler cavity field symmetrization data are presented: and details of the cavity microtuners and the high power rectangular waveguide network components, are described. {copyright} {ital 1999 American Institute of Physics.}
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FG03-97ER82389
- OSTI ID:
- 687957
- Report Number(s):
- CONF-980742--
- Journal Information:
- AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 472; ISSN APCPCS; ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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