SRF2011 - List of Authors (Eddy, N.)

Paper	Title	Page
MOPO060	Higher Order Modes for Beam Diagnostics in Third Harmonic 3.9 GHz Accelerating Modules	239
	N. Baboi, P. Zhang DESY, Hamburg, Germany N. Eddy Fermilab, Batavia, USA T. Flisgen, H.-W. Glock Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany R.M. Jones, I.R.R. Shinton UMAN, Manchester, United Kingdom
	Funding: This work is supported in part by the European Commission under the FP7 Research Infrastructures project EuCARD, grant agreement 227579. An international team is currently investigating the best way to use Higher Order Modes (HOM) for beam diagnostics in 3.9 GHz cavities. HOMs are excited by charged particles when passing through an accelerating structure. Third harmonic cavities working at 3.9 GHz have been installed in FLASH to linearize the bunch energy profile. A proof-of-principle of using HOMs for beam monitoring has been made at FLASH in the TESLA 1.3 GHz cavities. Since the wakefields generated in the 3.9 GHz cavities are significantly larger, their impact on the beam should be carefully minimized. Therefore our target is to monitor HOMs and minimize them by aligning the beam on the cavity axis. The difficulty is that, in comparison to the 1.3 GHz cavities, the HOM-spectrum is dense, making it difficult to identify individual modes. Also, most modes propagate through the whole cryo-module containing several cavities, making it difficult to measure local beam properties. In this paper the options for the HOM-based beam position monitors are discussed.

THPO040	A Wire Position Monitor System for the 1.3GHz Tesla-Style Cryomodule at the Fermilab New Muon Lab	806
	N. Eddy, B.J. Fellenz, P.S. Prieto, A. Semenov, D.C. Voy, M. Wendt Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance LLC under contract #DE-AC02-07CH11359 with the US Department of Energy. A wire position monitor system was put in place to monitor the motion of the 300mm return pipe in the first 1.3GHz Tesla-style cryomodule currently under RF testing at the Fermilab New Muon Lab. An overview of the system is given along with initial results including cooldown and subsequent testing.

Paper

Title

Page

Higher Order Modes for Beam Diagnostics in Third Harmonic 3.9 GHz Accelerating Modules

239

N. Baboi, P. Zhang
DESY, Hamburg, Germany
N. Eddy
Fermilab, Batavia, USA
T. Flisgen, H.-W. Glock
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
R.M. Jones, I.R.R. Shinton
UMAN, Manchester, United Kingdom

Funding: This work is supported in part by the European Commission under the FP7 Research Infrastructures project EuCARD, grant agreement 227579.
An international team is currently investigating the best way to use Higher Order Modes (HOM) for beam diagnostics in 3.9 GHz cavities. HOMs are excited by charged particles when passing through an accelerating structure. Third harmonic cavities working at 3.9 GHz have been installed in FLASH to linearize the bunch energy profile. A proof-of-principle of using HOMs for beam monitoring has been made at FLASH in the TESLA 1.3 GHz cavities. Since the wakefields generated in the 3.9 GHz cavities are significantly larger, their impact on the beam should be carefully minimized. Therefore our target is to monitor HOMs and minimize them by aligning the beam on the cavity axis. The difficulty is that, in comparison to the 1.3 GHz cavities, the HOM-spectrum is dense, making it difficult to identify individual modes. Also, most modes propagate through the whole cryo-module containing several cavities, making it difficult to measure local beam properties. In this paper the options for the HOM-based beam position monitors are discussed.

THPO040

A Wire Position Monitor System for the 1.3GHz Tesla-Style Cryomodule at the Fermilab New Muon Lab

806

N. Eddy, B.J. Fellenz, P.S. Prieto, A. Semenov, D.C. Voy, M. Wendt
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance LLC under contract #DE-AC02-07CH11359 with the US Department of Energy.
A wire position monitor system was put in place to monitor the motion of the 300mm return pipe in the first 1.3GHz Tesla-style cryomodule currently under RF testing at the Fermilab New Muon Lab. An overview of the system is given along with initial results including cooldown and subsequent testing.