| C. Simon, S. Chel, M. Luong, O. Napoly, J. Novo, D. Roudier, N. Baboi, D. Noelle, N. Mildner, K. Zapfe and N. Rouvière |
A high resolution Beam Position Monitor (BPM) is necessary for the beam-based alignment systems
of high energy and low emittance electron linacs. Such a monitor is developed in the framework
of the European CARE/SRF programme, in a close collaboration between DESY and CEA/DSM/DAPNIA.
This monitor is a radiofrequency re-entrant cavity, which can be used either at room or cryogenic
temperature, in an environment where dust particle contamination has to be avoided, such as
superconducting cavities in a cryomodule. A first prototype of a re-entrant BPM has already
delivered measurements at 2K inside the first cryomodule (ACC1) on the TESLA Test Facility 2 (TTF2).
The performances of this BPM are analyzed both experimentally and theoretically, and the limitations
of this existing system clearly identified. A new cavity and new electronics have been designed in order
to improve the position resolution down to 1 μm and the damping time down to 10 ns. |
