| The probe beam linac of the CTF3 test facility, named CALIFES, is developed by the CEA Saclay, the
LAL Orsay and CERN to deliver short bunches (0.75 ps) with a charge of 0.6 nC to the CLIC 12 GHz accelerating structures. To setup the machine and obtain a precise beam handling, six high resolution beam position monitors (BPMs), based on a radiofrequency reentrant cavity with an aperture of 18 mm, are installed along the linac. The associated electronics is composed of an analog signal processing electronics with a multiplexing to control the six monitors. Due to
mechanical tolerances, dipole mode frequencies are
different for each BPMs, 100 MHz intermediate IF frequency is, therefore, used so that monitors operate in single and multi-bunch modes. Digitalised signals from acquisition boards are made available to the operation crew thanks to the OASIS interfaces. In this paper, the BPMs acquisition and the signal post processing, to extract the beam position, will be discussed and first beam tests will be presented. |
