First acceleration with the SwissFEL C-band module
On Thursday 08/09/2016, the first C-band module boosted an electron beam from 150MeV to 390 MeV. This is the first beam acceleration test of a C-band module in PSI and is an important milestone for the project, since the main accelerator consists of 26 C-band modules of the same kind. In the module, the RF pulse is first generated by a pulsed modulator- klystron amplifier, placed in the technical gallery, and is guided to the pulse compressor (BOC), where it is compressed by a factor four and split to the four accelerating cavities in the beam tunnel. The 104 accelerating cavities are two meters long and have been developed at PSI, produced together with the VDL Enabling Technologies Group Switzerland AG. The 26 BOCs have been developed and fully produced at PSI. An outstanding feature of the SwissFEL C-band module is that for the first time, accelerating structures and pulse compressors have been produced on frequency, i.e. without any tuning of the frequency. During the acceleration test, the module was operating at the nominal RF power setting of 36 MW and 3 microseconds pulse at 5.712GHz and a repetition rate of 10Hz. The measured beam energy gain was 240 MeV, with excellent agreement with the expected value of 233 MeV. The installation of the C-band modules has been completed with the mounting of the last unit on Tuesday 13/09/2016.