IPAC2013 - List of Authors (Lefevre, T.)

Paper	Title	Page
MOPME077	Electro-0ptical Bunch Profile Measurement at CTF3	658
	R. Pan, A. Andersson, W. Farabolini, A. Goldblatt, T. Lefèvre, M. Martyanov, S. Mazzoni, S.F. Rey, L. Timeo CERN, Geneva, Switzerland W.A. Gillespie, R. Pan, D.A. Walsh University of Dundee, Nethergate, Dundee, Scotland, United Kingdom S.P. Jamison STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	A new electro-optic bunch profile monitor has recently been installed in CLIC Test Facility 3 at CERN. The monitor is based on an electro-optic spectral decoding scheme which reconstructs the longitudinal profile of the electron bunch by measuring its Coulomb field. The system uses a 780 nm fibre laser system, transported over a 20m long distance to the interaction chamber, where a ZnTe crystal is positioned close to the beam. The assembly also contains a traditional OTR screen, which is coupled to a second optical line and used to adjust the temporal overlap between the laser and the electron pulse. This paper presents the detection system in detail, as well as reporting on the first measurements performed with beam.

MOPWA051	ZEMAX Simulations for an Optical System for a Diffraction Radiation Monitor at CesrTA	789
	T. Aumeyr, V. Karataev JAI, Egham, Surrey, United Kingdom M.G. Billing CLASSE, Ithaca, New York, USA L.M. Bobb, B. Bolzon, T. Lefèvre, S. Mazzoni CERN, Geneva, Switzerland
	Diffraction Radiation (DR) is produced when a relativistic charged particle moves in the vicinity of a medium. The target atoms are polarized by the electric field of the charged particle, which then oscillate thus emitting radiation with a very broad spectrum. The spatial-spectral properties of DR are sensitive to various electron beam parameters. Since the energy loss due to DR is so small that the electron beam parameters are unchanged, DR can be used to develop non-invasive diagnostic tools. The aim of this project is to measure the transverse (vertical) beam size using incoherent DR. To achieve the micron-scale resolution required by CLIC, DR in the UV and X-ray spectral-range must be studied. During the next few years, experimental validation of such a scheme will be conducted on the CesrTA at Cornell University, USA. This paper reports on simulations carried out with ZEMAX, studying the optical system used to image the emitted radiation.

TUPFI063	Electromagnetic Coupling between High Intensity LHC Beams and the Synchrotron Radiation Monitor Light Extraction System	1493
	F. Roncarolo, W. Andreazza, A. Bertarelli, E. Bravin, F. Caspers, M. Garlaschè, A. Goldblatt, J-J. Gras, O.R. Jones, T. Lefèvre, E. Métral, A.A. Nosych, B. Salvant, G. Trad, R. Veness, C. Vollinger, M. Wendt CERN, Geneva, Switzerland
	The CERN LHC is equipped with two Synchrotron Radiation Monitor systems used to characterise transverse and longitudinal beam distributions. Since the end of the 2011 LHC run the light extraction system, based on a retractable mirror, has suffered deformation and mechanical failure that is correlated to the increase in beam intensity. Temperature probes have associated these observations to a strong heating of the mirror support with a dependence on the longitudinal bunch length and shape, indicating the origin as electromagnetic coupling between the beam and the structure. This paper combines all this information with the aim of characterising and improving the system in view of its upgrade during the current LHC shutdown. Beam-based observations are presented along with electromagnetic and thermomechanical simulations and complemented by laboratory measurements, including the study of the RF properties of different mirror bulk and coating materials.

Paper

Title

Page

Electro-0ptical Bunch Profile Measurement at CTF3

658

R. Pan, A. Andersson, W. Farabolini, A. Goldblatt, T. Lefèvre, M. Martyanov, S. Mazzoni, S.F. Rey, L. Timeo
CERN, Geneva, Switzerland
W.A. Gillespie, R. Pan, D.A. Walsh
University of Dundee, Nethergate, Dundee, Scotland, United Kingdom
S.P. Jamison
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

A new electro-optic bunch profile monitor has recently been installed in CLIC Test Facility 3 at CERN. The monitor is based on an electro-optic spectral decoding scheme which reconstructs the longitudinal profile of the electron bunch by measuring its Coulomb field. The system uses a 780 nm fibre laser system, transported over a 20m long distance to the interaction chamber, where a ZnTe crystal is positioned close to the beam. The assembly also contains a traditional OTR screen, which is coupled to a second optical line and used to adjust the temporal overlap between the laser and the electron pulse. This paper presents the detection system in detail, as well as reporting on the first measurements performed with beam.

MOPWA051

ZEMAX Simulations for an Optical System for a Diffraction Radiation Monitor at CesrTA

789

T. Aumeyr, V. Karataev
JAI, Egham, Surrey, United Kingdom
M.G. Billing
CLASSE, Ithaca, New York, USA
L.M. Bobb, B. Bolzon, T. Lefèvre, S. Mazzoni
CERN, Geneva, Switzerland

Diffraction Radiation (DR) is produced when a relativistic charged particle moves in the vicinity of a medium. The target atoms are polarized by the electric field of the charged particle, which then oscillate thus emitting radiation with a very broad spectrum. The spatial-spectral properties of DR are sensitive to various electron beam parameters. Since the energy loss due to DR is so small that the electron beam parameters are unchanged, DR can be used to develop non-invasive diagnostic tools. The aim of this project is to measure the transverse (vertical) beam size using incoherent DR. To achieve the micron-scale resolution required by CLIC, DR in the UV and X-ray spectral-range must be studied. During the next few years, experimental validation of such a scheme will be conducted on the CesrTA at Cornell University, USA. This paper reports on simulations carried out with ZEMAX, studying the optical system used to image the emitted radiation.

TUPFI063

Electromagnetic Coupling between High Intensity LHC Beams and the Synchrotron Radiation Monitor Light Extraction System

1493

F. Roncarolo, W. Andreazza, A. Bertarelli, E. Bravin, F. Caspers, M. Garlaschè, A. Goldblatt, J-J. Gras, O.R. Jones, T. Lefèvre, E. Métral, A.A. Nosych, B. Salvant, G. Trad, R. Veness, C. Vollinger, M. Wendt
CERN, Geneva, Switzerland

The CERN LHC is equipped with two Synchrotron Radiation Monitor systems used to characterise transverse and longitudinal beam distributions. Since the end of the 2011 LHC run the light extraction system, based on a retractable mirror, has suffered deformation and mechanical failure that is correlated to the increase in beam intensity. Temperature probes have associated these observations to a strong heating of the mirror support with a dependence on the longitudinal bunch length and shape, indicating the origin as electromagnetic coupling between the beam and the structure. This paper combines all this information with the aim of characterising and improving the system in view of its upgrade during the current LHC shutdown. Beam-based observations are presented along with electromagnetic and thermomechanical simulations and complemented by laboratory measurements, including the study of the RF properties of different mirror bulk and coating materials.