Język
en
Treść
At free-electron linear accelerators, various High Or-
der Modes (HOM) - both monopole and dipole - are ex-
cited. Extensive studies at DESY have shown that mon-
itoring and analysis of some of these modes can be used
for different applications including Beam Position Mon-
itors (BPMs) and the reduction of wake-fields, the mea-
surement of the beam phase with-respect-to RF signal in
cavities, and the measurement of cavity alignment in the
1.3 GHz cryo-modules. Three frequencies were chosen
for further experiments: the 1.3 GHz base frequency from
the klystron, the 1.7 GHz dipole mode and the 2.4 GHz
monopole mode. In order to realize the monitoring and
analysis requirements, very high resolution measurements
in amplitude, phase and shape (time resolution) are re-
quired for all three frequencies simultaneously. In this pa-
per, we present the new HOM electronics prototype includ-
ing a microstrip and stripline RF tri-passband filter design
and measurements and the specialized MTCA.4 Rear Tran-
sition Module for HOM measurements with an ultra-fast
high-resolution AMC digitizer.
