IBIC2012 - List of Authors (Gerth, C.)

Paper	Title	Page
MOPA47	Planar Transmission Line BPM for Horizontal Aperture Chicane for XFEL	168
	A. Angelovski, R. Jakoby, A. Penirschke TU Darmstadt, Darmstadt, Germany C. Gerth, U. Mavrič, C. Sydlo DESY, Hamburg, Germany
	In order to obtain ultra-short bunches in the Free Electron Laser FLASH at DESY, the electron beam is compressed in magnetic chicanes. Precise knowledge of the beam position in the chicane is of great significance for the longitudinal dynamics control. In the current implementation cylindrical pickup-striplines mounted perpendicularly to the beam are used as a Beam Position Monitor (BPM)(). One can determine the horizontal beam position by measuring the phase difference of the beam induced signal at opposite ends of a pickup. Due to the different electrical and mechanical requirements for the European XFEL a new BPM has to be developed. In this paper, we present the design and analysis of a planar transmission line structure which is planned to be used as a BPM in the European XFEL. The planar design of the pickups can provide for proper impedance match to the subsequent electronics as well as sufficient mechanical stability along the aperture when using alumina substrates. A scaled non-hermetic prototype of the BPM is built and characterized by scattering parameters. The measurement results are compared to simulations obtained by CST STUDIO SUITE®. () K. Hacker at el, Proceedings of DIPAC 2007, Venice, Italy 2007, p.108

MOPB82	Bunch-Compressor Transverse Profile Monitors of the SwissFEL Injector Test Facility	271
	G.L. Orlandi, M. Aiba, S. Bettoni, B. Beutner, H. Brands, R. Ischebeck, P. Peier, E. Prat, T. Schietinger, V. Schlott, V.G. Thominet PSI, Villigen PSI, Switzerland C. Gerth DESY, Hamburg, Germany
	The 250 MeV SwissFEL Injector Test Facility (SITF) is the test bed of the future 5.7 GeV SwissFEL linac that will drive a coherent FEL light source in the wavelength range 7-0.7 and 0.7-0.1 nm. Aim of the SITF is to demonstrate the technical feasibility of producing and measuring 10 or 200pC electron bunches with normalized emittance down to 0.25 μm. A further goal is to demonstrate that the electron beam quality is preserved in the acceleration process, in the X-Band linearizer and the magnetic compression from about 10 ps down to 200 fs. The SITF movable magnetic bunch-compressor is equipped with several CCD/CMOS cameras for monitoring the beam transverse profile and determining the beam energy spread: a Ce:YAG screen and an OTR screen camera at the mid-point of the bunch compressor and a SR camera imaging in the visible the Synchrotron Radiation emitted by the electron beam crossing the third dipole. Results on the commissioning of such instrumentations, in particular in the low charge limit, and measurements of the beam energy spread vs. the compression factor will be presented.

Paper

Title

Page

Planar Transmission Line BPM for Horizontal Aperture Chicane for XFEL

168

A. Angelovski, R. Jakoby, A. Penirschke
TU Darmstadt, Darmstadt, Germany
C. Gerth, U. Mavrič, C. Sydlo
DESY, Hamburg, Germany

In order to obtain ultra-short bunches in the Free Electron Laser FLASH at DESY, the electron beam is compressed in magnetic chicanes. Precise knowledge of the beam position in the chicane is of great significance for the longitudinal dynamics control. In the current implementation cylindrical pickup-striplines mounted perpendicularly to the beam are used as a Beam Position Monitor (BPM)(*). One can determine the horizontal beam position by measuring the phase difference of the beam induced signal at opposite ends of a pickup. Due to the different electrical and mechanical requirements for the European XFEL a new BPM has to be developed. In this paper, we present the design and analysis of a planar transmission line structure which is planned to be used as a BPM in the European XFEL. The planar design of the pickups can provide for proper impedance match to the subsequent electronics as well as sufficient mechanical stability along the aperture when using alumina substrates. A scaled non-hermetic prototype of the BPM is built and characterized by scattering parameters. The measurement results are compared to simulations obtained by CST STUDIO SUITE®.
(*) K. Hacker at el, Proceedings of DIPAC 2007, Venice, Italy 2007, p.108

MOPB82

Bunch-Compressor Transverse Profile Monitors of the SwissFEL Injector Test Facility

271

G.L. Orlandi, M. Aiba, S. Bettoni, B. Beutner, H. Brands, R. Ischebeck, P. Peier, E. Prat, T. Schietinger, V. Schlott, V.G. Thominet
PSI, Villigen PSI, Switzerland
C. Gerth
DESY, Hamburg, Germany

The 250 MeV SwissFEL Injector Test Facility (SITF) is the test bed of the future 5.7 GeV SwissFEL linac that will drive a coherent FEL light source in the wavelength range 7-0.7 and 0.7-0.1 nm. Aim of the SITF is to demonstrate the technical feasibility of producing and measuring 10 or 200pC electron bunches with normalized emittance down to 0.25 μm. A further goal is to demonstrate that the electron beam quality is preserved in the acceleration process, in the X-Band linearizer and the magnetic compression from about 10 ps down to 200 fs. The SITF movable magnetic bunch-compressor is equipped with several CCD/CMOS cameras for monitoring the beam transverse profile and determining the beam energy spread: a Ce:YAG screen and an OTR screen camera at the mid-point of the bunch compressor and a SR camera imaging in the visible the Synchrotron Radiation emitted by the electron beam crossing the third dipole. Results on the commissioning of such instrumentations, in particular in the low charge limit, and measurements of the beam energy spread vs. the compression factor will be presented.