DIPAC2011 - List of Authors (Baboi, N.)

Paper	Title	Page
MOPD09	Electron Beam Diagnostics for FLASH II	53
	N. Baboi, D. Nölle DESY, Hamburg, Germany
	Up to now, the FLASH linac serves one SASE (Self-Amplified Spontaneous Emission) undulator. The radiation produced can be guided to one of 5 beamlines in the experimental hall. In order to increase the availability of the machine, an extension, FLASH II, will be built in the next few years. A second undulator section will be built to generate SASE light. A HHG (High Harmonic Generation) laser will alternatively be used to produce seeded radiation in the undulators. The electron beam diagnostics in FLASH II has to enable the precise control of the beam position, size, timing, as well as the overlap of the electron beam with the HHG laser. The losses have to be kept under control, and the beam has to terminate safely in the beam dump. In comparison to FLASH, which was designed to run with rather high charge, the dynamic range of the diagnostics has to be between 0.1 to 1 nC, similar to the European XFEL. This paper gives an overview of the diagnostics for FLASH II.

MOPD17	Beam-based HOM Study in Third Harmonic SC Cavities for Beam Alignment at FLASH	77
	P. Zhang, R.M. Jones, I.R.R. Shinton UMAN, Manchester, United Kingdom N. Baboi, B. Lorbeer, P. Zhang DESY, Hamburg, Germany H. Ecklebe, T. Flisgen, H.-W. Glock Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
	Funding: Work supported by European Commission under the FP7 Research Infrastructures grant agreement No.227579. An electron beam entering an accelerator cavity excites higher order modes (HOM). These are radiated to HOM couplers, subsequently damped, and can also be used to facilitate beam monitoring. The modes which deflect the beam transversely are the focus of this study and are used to monitor the beam position. Results are presented on the first analysis of beam alignment based on HOM signals from the third harmonic cavities at FLASH. The electrical center of each mode is ascertained by moving the beam to minimize the HOM signal detected. A single electron bunch per RF pulse is used.

MOPD25	Diode Down-mixing of HOM Coupler Signals for Beam Position Determination in 1.3-GHz- and 3.9-GHz-Cavities at FLASH	101
	H.-W. Glock, H. Ecklebe, T. Flisgen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany N. Baboi, P. Zhang DESY, Hamburg, Germany
	Funding: work supported by BMBF under contract 05K10HRC and by European Commission under the FP7 Research Infrastructures grant agreement No.227579 Beam excited signals available at the HOM coupler ports of superconducting accelerating cavities cover a wide frequency range and carry information about (amongst others) transverse beam position. Down-mixing these signals using detector diodes is a mean to measure with standard and non-specific oscilloscope technology the time dependency of the power leaving the HOM coupler. Experiments undertaken at the accelerator modules ACC1 and ACC39 at FLASH demonstrated the possibility to extract beam position data out of low-frequency signals sampled with such a setup. These experiments as part of an ongoing study are described together with mathematical details of the evaluation scheme.

TUPD41	The Beam Halo Monitor for FLASH	395
	A. Ignatenko, N. Baboi, O. Hensler, M. Schmitz, K. Wittenburg DESY, Hamburg, Germany H.M. Henschel, W. Lange DESY Zeuthen, Zeuthen, Germany A. Ignatenko, W. Lohmann BTU, Cottbus, Germany S. Schuwalow University of Hamburg, Hamburg, Germany
	The Beam Halo Monitor (BHM) for FLASH based on pCVD diamond and monocrystalline sapphire sensors has been successfully commissioned and is in operation. It is a part of the beam dump diagnostics system that ensures safe beam dumping. The description of the BHM and experience gained during its operation are given in this paper.

Paper

Title

Page

Electron Beam Diagnostics for FLASH II

53

N. Baboi, D. Nölle
DESY, Hamburg, Germany

Up to now, the FLASH linac serves one SASE (Self-Amplified Spontaneous Emission) undulator. The radiation produced can be guided to one of 5 beamlines in the experimental hall. In order to increase the availability of the machine, an extension, FLASH II, will be built in the next few years. A second undulator section will be built to generate SASE light. A HHG (High Harmonic Generation) laser will alternatively be used to produce seeded radiation in the undulators. The electron beam diagnostics in FLASH II has to enable the precise control of the beam position, size, timing, as well as the overlap of the electron beam with the HHG laser. The losses have to be kept under control, and the beam has to terminate safely in the beam dump. In comparison to FLASH, which was designed to run with rather high charge, the dynamic range of the diagnostics has to be between 0.1 to 1 nC, similar to the European XFEL. This paper gives an overview of the diagnostics for FLASH II.

MOPD17

Beam-based HOM Study in Third Harmonic SC Cavities for Beam Alignment at FLASH

77

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

Funding: Work supported by European Commission under the FP7 Research Infrastructures grant agreement No.227579.
An electron beam entering an accelerator cavity excites higher order modes (HOM). These are radiated to HOM couplers, subsequently damped, and can also be used to facilitate beam monitoring. The modes which deflect the beam transversely are the focus of this study and are used to monitor the beam position. Results are presented on the first analysis of beam alignment based on HOM signals from the third harmonic cavities at FLASH. The electrical center of each mode is ascertained by moving the beam to minimize the HOM signal detected. A single electron bunch per RF pulse is used.

MOPD25

Diode Down-mixing of HOM Coupler Signals for Beam Position Determination in 1.3-GHz- and 3.9-GHz-Cavities at FLASH

101

H.-W. Glock, H. Ecklebe, T. Flisgen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
N. Baboi, P. Zhang
DESY, Hamburg, Germany

Funding: work supported by BMBF under contract 05K10HRC and by European Commission under the FP7 Research Infrastructures grant agreement No.227579
Beam excited signals available at the HOM coupler ports of superconducting accelerating cavities cover a wide frequency range and carry information about (amongst others) transverse beam position. Down-mixing these signals using detector diodes is a mean to measure with standard and non-specific oscilloscope technology the time dependency of the power leaving the HOM coupler. Experiments undertaken at the accelerator modules ACC1 and ACC39 at FLASH demonstrated the possibility to extract beam position data out of low-frequency signals sampled with such a setup. These experiments as part of an ongoing study are described together with mathematical details of the evaluation scheme.

TUPD41

The Beam Halo Monitor for FLASH

395

A. Ignatenko, N. Baboi, O. Hensler, M. Schmitz, K. Wittenburg
DESY, Hamburg, Germany
H.M. Henschel, W. Lange
DESY Zeuthen, Zeuthen, Germany
A. Ignatenko, W. Lohmann
BTU, Cottbus, Germany
S. Schuwalow
University of Hamburg, Hamburg, Germany

The Beam Halo Monitor (BHM) for FLASH based on pCVD diamond and monocrystalline sapphire sensors has been successfully commissioned and is in operation. It is a part of the beam dump diagnostics system that ensures safe beam dumping. The description of the BHM and experience gained during its operation are given in this paper.