| Paper | Title | Page |
|---|
| TUP28 | 1.3 GHz Cavity Weld to Helium Vessel | 192 |
| | - A. Schmidt, A. Matheisen, H. Kaiser, W. Menck, G. Weichert
DESY Hamburg
| |
| | At DESY Hamburg superconducting accelerator units
(Cavities) are under development for the FLASH
accelerator and the XFEL project. For accelerator
application each cavity is equipped with an individual
Helium vessel and cooled by bath cooling with Helium at
2K [1]. The improvements of cavity performance like
gradient and quality factors require improvements on the
processes of completion the He tank as well. An overview
on the sequences and processes for tank welding for the
DESY 1.3 GHz Cavities will be given. | |
| WEP17 | Considerations on the third harmonic RF of the European XFEL | 481 |
| | - E. Vogel, M. Dohlus, M. Huening, K. Jensch, A. Matheisen, W. -D. Moeller, A. Schmidt, W. Singer
DESY Hamburg - H. Edwards, E. Harms, T. Khabiboulline
Fermilab
| |
| | Ultra short bunches with high peak current are required for the creation of high brilliance coherent light in the x-ray range in undulators. At the European x-ray free electron laser (XFEL) they will be obtained by a two stage bunch compression scheme based on off the rf field crest acceleration and transverse magnetic chicanes. The deviation of the rf field's sine shape from a straight line leads to long bunch tails and reduce peak current. This effect will be eliminated by adding a third harmonic rf system. The paper surveys the basic principle for the third harmonic rf, the most relevant design parameters, the actual status of beam physical examinations and potential concepts for the technical realization. | |