Preliminary design of the CLIC drive-beam transfer line

In the drive-beam generation complex of CLIC there is an important beam transfer line between the drive-beam accelerator and the drive-beam decelerators, where the 30 GHz RF power is generated in the decelerator structures. The design proposed for this transport system is based on building blocks or beam optics subsystems, which have been individually studied in detail and can be combined in order to cover specific functions. One function consists of bending the beams wherever required by the geometrical layout, so as to preserve the bunch length and keep the bending are compact and compatible with acceptable synchrotron radiation. Other functions are to adjust the path length of each drive beam for synchronism with the main-linac beam and to compress or stretch the bunch according to the needs. Furthermore, there are vertical and horizontal beam translations, isochronous or acting as a compressor, and p-function transformers for matching the optics. All these functions are necessary in the drive-beam transfer that precedes injection into the decelerators.