IBIC2012 - List of Authors (Schlott, V.)

Paper

Title

Page

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.

MOPB87

Development and First Tests of a High Sensitivity Charge Monitor for SwissFEL

287

S. Artinian, J.F. Bergoz, F. Stulle
BERGOZ Instrumentation, Saint Genis Pouilly, France
P. Pollet, V. Schlott
PSI, Villigen PSI, Switzerland

The compact X-ray free electron laser SwissFEL, which is presently under development at the Paul Scherrer Institut (PSI) in Villigen, Switzerland, will operate at comparably low charges, allowing the compression of the electron bunches to a few femto-seconds (nominal 200 pC mode) and even towards the atto-second range (short bunch 10 pC mode). A high precision charge measurement turns out to be a challenge, especially in the presence of dark currents, which may occur from high gradient RF gun and accelerating structure operation. In response to this challenge, a higher sensitivity charge transformer and new beam charge monitor electronics were developed in collaboration between Bergoz Instrumentation and PSI. The Turbo-ICT captures sub-pC bunch charge thanks to a new magnetic alloy exhibiting very low core loss. Transmission over a carrier using narrow-band cable television technique preserves the signal integrity from the Turbo-ICT to the BCM-RF. Electro-magnetic and RF interferences are strongly attenuated; the dark current signal is suppressed. First beam test results, which have been performed at the SwissFEL Test Injector Facility (STIF), are presented in this contribution.

TUCC03

Design and Expected Performance of the New SLS Beam Size Monitor

307

N. Milas, M. Rohrer, Á. Saá Hernández, V. Schlott, A. Streun
PSI, Villigen PSI, Switzerland
Å. Andersson, J. Breunlin
MAX-lab, Lund, Sweden

The vertical emittance minimization campaign at SLS, realized in the context of the TIARA WP6, has already achieved the world's smallest vertical emittance of 0.9 pm in a synchrotron light source. The minimum value reached for the vertical emittance is only five times bigger than the quantum limit of 0.2 pm. However, the resolution limit of the present SLS emittance monitor has also been reached thus, to further continue the emittance minimization program the construction of an improved second monitor is necessary. In this paper we present the design and studies on the performance of this new monitor based on the image formation method using vertically polarized synchrotron radiation in the vis-UV spectral regimes. This monitor includes a new feature, providing the possibility of performing full interferometric measurement by the use of a set of vertical obstacles that can be driven on the light path. Simulations results are used to investigate the possible source of errors and their effects on imaging and the determination of the beam height. We also present the expected performance, in term of emittance accuracy and precision, and discuss possible design limitations.

Slides TUCC03 [8.497 MB]

Paper	Title	Page
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.

MOPB87	Development and First Tests of a High Sensitivity Charge Monitor for SwissFEL	287
	S. Artinian, J.F. Bergoz, F. Stulle BERGOZ Instrumentation, Saint Genis Pouilly, France P. Pollet, V. Schlott PSI, Villigen PSI, Switzerland
	The compact X-ray free electron laser SwissFEL, which is presently under development at the Paul Scherrer Institut (PSI) in Villigen, Switzerland, will operate at comparably low charges, allowing the compression of the electron bunches to a few femto-seconds (nominal 200 pC mode) and even towards the atto-second range (short bunch 10 pC mode). A high precision charge measurement turns out to be a challenge, especially in the presence of dark currents, which may occur from high gradient RF gun and accelerating structure operation. In response to this challenge, a higher sensitivity charge transformer and new beam charge monitor electronics were developed in collaboration between Bergoz Instrumentation and PSI. The Turbo-ICT captures sub-pC bunch charge thanks to a new magnetic alloy exhibiting very low core loss. Transmission over a carrier using narrow-band cable television technique preserves the signal integrity from the Turbo-ICT to the BCM-RF. Electro-magnetic and RF interferences are strongly attenuated; the dark current signal is suppressed. First beam test results, which have been performed at the SwissFEL Test Injector Facility (STIF), are presented in this contribution.

TUCC03	Design and Expected Performance of the New SLS Beam Size Monitor	307
	N. Milas, M. Rohrer, Á. Saá Hernández, V. Schlott, A. Streun PSI, Villigen PSI, Switzerland Å. Andersson, J. Breunlin MAX-lab, Lund, Sweden
	The vertical emittance minimization campaign at SLS, realized in the context of the TIARA WP6, has already achieved the world's smallest vertical emittance of 0.9 pm in a synchrotron light source. The minimum value reached for the vertical emittance is only five times bigger than the quantum limit of 0.2 pm. However, the resolution limit of the present SLS emittance monitor has also been reached thus, to further continue the emittance minimization program the construction of an improved second monitor is necessary. In this paper we present the design and studies on the performance of this new monitor based on the image formation method using vertically polarized synchrotron radiation in the vis-UV spectral regimes. This monitor includes a new feature, providing the possibility of performing full interferometric measurement by the use of a set of vertical obstacles that can be driven on the light path. Simulations results are used to investigate the possible source of errors and their effects on imaging and the determination of the beam height. We also present the expected performance, in term of emittance accuracy and precision, and discuss possible design limitations.
	Slides TUCC03 [8.497 MB]