TY - CPAPER
AU - Baboi, N.
AU - Eddy, N.
AU - Fellenz, B.J.
AU - Hensler, O.
AU - Shi, L.
AU - Wamsat, T.
AU - Zhang, P.
TI - Commissioning of the Electronics for HOM-based Beam Diagnostics at the 3.9 GHz Accelerating Module at FLASH
J2 - Proc. of IBIC2014
AB - Transverse Higher Order Modes (HOM) excited by electron beams in the 3.9 GHz accelerating cavities at FLASH may damage the beam quality. They can be reduced by extracting their energy through special couplers and by aligning the beam in the cavity. Electronics has been designed at FNAL for monitoring some of the potentially most damaging HOMs. This may be used for beam centering and therefore reducing the HOM effects. Moreover, the signals can be potentially calibrated into beam offset, so that they could be used as beam position monitors (HOM-BPM). The specifications of the monitors have been defined during an extensive study on the 4-cavity accelerating module installed at FLASH. Signals around 5.44 GHz have been chosen for higher precision measurements. However these signals propagate into the entire 1.2 m long module. Therefore in addition modes at about 9 GHz were selected for localized measurements in each cavity. The electronics has been recently installed at FLASH. The commissioning results will be presented in this paper. Instabilities previously observed in a test electronics as well as the HOM-BPMs in 1.3 GHz cavities will also be investigated*. This electronics will also serve as a prototype for the electronics developed for the 3.9 GHz cavities at the European XFEL**.
PB - JACoW
CY - Geneva, Switzerland
SP - 311
EP - 314
KW - HOM
KW - electronics
KW - cavity
KW - alignment
KW - dipole
DA - 2014/10
PY - 2014
SN - 978-3-95450-141-0
UR - http://jacow.org/IBIC2014/papers/tupf06.pdf
ER -