IPAC2011 - List of Authors (Couprie, M.-E.)

Paper	Title	Page
MOPS048	Microbunching Instability Studies at SOLEIL	709
	C. Evain, J. Barros, J.B. Brubach, L. Cassinari, M.-E. Couprie, G. Creff, M. Labat, A. Loulergue, L. Manceron, R. Nagaoka, P. Roy, M.-A. Tordeux SOLEIL, Gif-sur-Yvette, France
	Microbunching instability arises in storage rings when the number of electrons in a bunch exceeds a threshold value. Its signature, i.e. a strong and irregular emission of Coherent Synchrotron Radiation (CSR) in the Terahertz (THz) domain, is studied at SOLEIL on the AILES infrared beamline, with the storage ring tuned in a low-alpha configuration (used to get shorter electron bunch). The comparison of this observed THz CSR with numerical simulations of the longitudinal electron bunch dynamics, permits to put in evidence that during the instability a modulation appears and drifts in the longitudinal profile of the electron bunch. The understanding of this instability is important as it limits some operation of the storage rings. Indeed the induced fluctuations prevent the use of THz on the far IR beamline at high current per bunch. And in normal alpha operation this instability may spoil the electron/laser interaction effects used to get femtosecond and/or coherent pulse in storage rings (with slicing, Coherent Harmonic Generation or EEHG schemes on storage ring).

THPC007	Laser Electron Interaction Simulation for the Femtosecond Bunch Slicing on SOLEIL Storage Ring	2918
	J.F. Zhang, M.-E. Couprie, M. Labat, A. Loulergue, A. Nadji SOLEIL, Gif-sur-Yvette, France
	The interaction of an electron bunch and a laser in a wiggler (modulator) to generate a femtosecond slice is simulated for the slicing project on SOLEIL storage ring, using a code based on Monte-Carlo method and GENESIS. The results from these two codes are consistent with the theoretical values. The maximum modulated energy of the electron bunch and the number of electrons above a certain limit are studied for different wiggler and laser parameters. The transport of the 6D distribution of the sliced bunch from the modulator to the radiators are simulated using AT (Accelerator Toolbox) and ELEGANT, with synchrotron radiation on and taking into account the collective effects of the sliced bunch core.

THPC044	Operation and Performance Upgrade of the Soleil Storage Ring	3002
	A. Nadji, P. Brunelle, M.-E. Couprie, J.-C. Denard, J.-M. Filhol, J.-F. Lamarre, P. Lebasque, A. Loulergue, P. Marchand, L.S. Nadolski, R. Nagaoka, M.-A. Tordeux SOLEIL, Gif-sur-Yvette, France
	SOLEIL delivers photons to 24 beamlines. Up to 22 very diverse insertion devices (IDs) are now installed on the storage ring, and 4 more will come by summer 2011, including a Cryogenic undulator and an electromagnetic/permanent magnet helical undulator, both designed and built at SOLEIL. Work is continuing on beam dynamics and magnetic corrections to reduce the nonlinear effects of all these IDs. A new optics incorporating an additional quadrupole triplet in one long straight section has been successfully tested and will be put in operation by fall 2011. A new coupling correction will also be implemented to maintain the ratio of the vertical to the horizontal emittances at 1% for any IDs configuration. The electron beam orbit stability has been significantly improved reaching a residual noise of 300 nm RMS. Photon LIBERA modules of X-BPM located on the bends, will be integrated soon in the orbit feedback loops. 4905 hours have been delivered in 2010 to the beamlines with an availability of 96.3%. The user operation with the maximum current of 500 mA is foreseen to start by fall 2011, after the completion of the radiation safety tests of the beamlines.

THPC149	Development of PrFeB Cryogenic Undulator (CPMU) at SOLEIL	3233
	C. Benabderrahmane, P. Berteaud, N. Béchu, L. Chapuis, M.-E. Couprie, J.P. Daguerre, J.-M. Filhol, C. Herbeaux, A. Lestrade, M. Louvet, J.L. Marlats, K. Tavakoli, M. Valléau, D. Zerbib SOLEIL, Gif-sur-Yvette, France
	A R&D programme for the construction of a 2 m long 18 mm period CPMU is under progress at SOLEIL. The cryogenic undulator will provide photons in the region of 1.4 to 30 keV. It will be installed in the next few months on the long straight section (SDL13) of the storage ring, and could be used later on to produce photons for the NANOSCOPIUM beamline. The use of PrFeB which features a 1.35 T remanence (Br) at room temperature enables to increase the peak magnetic field at 5.5 mm minimum gap, from 1.04 T at room temperature to 1.15 T at a cryogenic temperature of 77 K. Praseodymium was chosen instead of Neodymium magnetic material, because it is more resistant against the appearance of the Spin Reorientation Transition. Different corrections were performed first at room temperature to adjust the phase error, the electron trajectory and to reduce the multipolar components. The mounting inside the vacuum chamber enables the fitting of a dedicated magnetic measurement bench to check the magnetic performance of the undulator at low temperature. The results of the magnetic measurements at low temperature and the comparison with the measurement at room temperature are reported.

THPC150	Review of Insertion Device Dedicated to HIgh Energy Photons at SOLEIL	3236
	O. Marcouillé, C. Benabderrahmane, P. Berteaud, F. Briquez, L. Chapuis, M.-E. Couprie, T.K. El Ajjouri, F. Marteau, M. Valléau, J. Vétéran SOLEIL, Gif-sur-Yvette, France
	Producing high energy photons between 10 keV and 70 keV is a challenging topic in a medium energy storage ring. It requires up-to-date measurement techniques and specific Insertion Device (ID) technologies to produce high magnetic fields and short periods. SOLEIL (2.75 GeV) has designed and built eight conventional in-vacuum hybrid undulators operating at high radiation harmonics and also one small gap multipole wiggler to produce high magnetic field. The construction has been progressively improved by the choice of new magnetic materials of better quality and higher magnetization, additional correction techniques and mechanical changes. A 2-m long full scale cryogenic undulator made of PrFeB and vanadium permendur has been built, measured, corrected and is to be tested on the beam. An additional wiggler dedicated for Slicing experiments has been designed. The required magnetic field is high enough to also consider the ID as a good candidate for the production of hard X-ray photons. This paper presents the ID dedicated for the high energy photons and their spectral performances.

THPC151	The 65 mm Period Electromagnetic/Permanent Magnets Helical Undulator at SOLEIL	3239
	F. Marteau, P. Berteaud, F. Bouvet, L. Chapuis, M.-E. Couprie, J.P. Daguerre, T.K. El Ajjouri, J.-M. Filhol, P. Lebasque, J.L. Marlats, A. Mary, K. Tavakoli SOLEIL, Gif-sur-Yvette, France
	SOLEIL prepares a new 65 mm period Electromagnetic/Permanent Magnets Helical Undulator (EMPHU), with a rapid switching at 5 Hz of the polarization required for dichroïsm experiments. The vertical field Bz is produced by coils fed by a fast switching power supply (designed and built in house), with a maximum current of 350 A and a polarity switching time shorter than 100 ms. The coils consist of 25 stacked copper layers shaped by water jet cutting. The current flows in 16 layers and 9 of them are cooled with thermal drain to a water piping. 4 additional power supplies feed 2 types of correction coils for the dynamic compensation of the field integrals, besides the ones for the termination. 1.28 T remanence NdFeB permanent magnets generate the horizontal field Bx. Peak Bz and Bx in the helical configuration reach 0.24 T at 14.7 mm minimum gap. Thermal modelling and measurements aim at keeping the magnet temperature constant. The static magnetic configuration was optimised using the ID_Builder software and the trajectory were checked for insuring a good reproducibility of the photon beam pointing when sweeping from one helicity to the other.

THPC152	Measurements of SOLEIL Insertion Devices using Pulsed Wire Method	3242
	M. Valléau, C. Benabderrahmane, M.-E. Couprie, O. Marcouillé, F. Marteau, J. Vétéran SOLEIL, Gif-sur-Yvette, France
	SOLEIL permanent magnets insertion devices are usually measured with a Hall probe in order to evaluate the electron angular deflexion, their deviation and the optical phase error, a figure of merit related to the quality of the insertion device radiation. A pulsed wire bench is developed at SOLEIL for reducing the measurement time of an undulator and for providing a measurement method without lateral access. A current pulse injected in a stretched wire inside the magnetic field area generates acoustic wave. The wire motion is detected by optical sensors whose signals are proportional to the local integral value. The signal-to-noise ratio of this method is often reduced due to several effects such as electronic noise, external and wire vibrations. However, following some hardware optimization it was possible to increase it up to almost 26 dB, making the method accurate and reproducible in order to realize efficient corrections. Measurements of first and second integral performed with Pulse wire, with Hall probe and with the electron beam are compared on three different types of insertions: an U18 in-vacuum cryogenic undulator, a HU60 APPLE-II undulator and a WSV50 in-vacuum wiggler.

Paper

Title

Page

Microbunching Instability Studies at SOLEIL

709

C. Evain, J. Barros, J.B. Brubach, L. Cassinari, M.-E. Couprie, G. Creff, M. Labat, A. Loulergue, L. Manceron, R. Nagaoka, P. Roy, M.-A. Tordeux
SOLEIL, Gif-sur-Yvette, France

Microbunching instability arises in storage rings when the number of electrons in a bunch exceeds a threshold value. Its signature, i.e. a strong and irregular emission of Coherent Synchrotron Radiation (CSR) in the Terahertz (THz) domain, is studied at SOLEIL on the AILES infrared beamline, with the storage ring tuned in a low-alpha configuration (used to get shorter electron bunch). The comparison of this observed THz CSR with numerical simulations of the longitudinal electron bunch dynamics, permits to put in evidence that during the instability a modulation appears and drifts in the longitudinal profile of the electron bunch. The understanding of this instability is important as it limits some operation of the storage rings. Indeed the induced fluctuations prevent the use of THz on the far IR beamline at high current per bunch. And in normal alpha operation this instability may spoil the electron/laser interaction effects used to get femtosecond and/or coherent pulse in storage rings (with slicing, Coherent Harmonic Generation or EEHG schemes on storage ring).

THPC007

Laser Electron Interaction Simulation for the Femtosecond Bunch Slicing on SOLEIL Storage Ring

2918

J.F. Zhang, M.-E. Couprie, M. Labat, A. Loulergue, A. Nadji
SOLEIL, Gif-sur-Yvette, France

The interaction of an electron bunch and a laser in a wiggler (modulator) to generate a femtosecond slice is simulated for the slicing project on SOLEIL storage ring, using a code based on Monte-Carlo method and GENESIS. The results from these two codes are consistent with the theoretical values. The maximum modulated energy of the electron bunch and the number of electrons above a certain limit are studied for different wiggler and laser parameters. The transport of the 6D distribution of the sliced bunch from the modulator to the radiators are simulated using AT (Accelerator Toolbox) and ELEGANT, with synchrotron radiation on and taking into account the collective effects of the sliced bunch core.

THPC044

Operation and Performance Upgrade of the Soleil Storage Ring

3002

A. Nadji, P. Brunelle, M.-E. Couprie, J.-C. Denard, J.-M. Filhol, J.-F. Lamarre, P. Lebasque, A. Loulergue, P. Marchand, L.S. Nadolski, R. Nagaoka, M.-A. Tordeux
SOLEIL, Gif-sur-Yvette, France

SOLEIL delivers photons to 24 beamlines. Up to 22 very diverse insertion devices (IDs) are now installed on the storage ring, and 4 more will come by summer 2011, including a Cryogenic undulator and an electromagnetic/permanent magnet helical undulator, both designed and built at SOLEIL. Work is continuing on beam dynamics and magnetic corrections to reduce the nonlinear effects of all these IDs. A new optics incorporating an additional quadrupole triplet in one long straight section has been successfully tested and will be put in operation by fall 2011. A new coupling correction will also be implemented to maintain the ratio of the vertical to the horizontal emittances at 1% for any IDs configuration. The electron beam orbit stability has been significantly improved reaching a residual noise of 300 nm RMS. Photon LIBERA modules of X-BPM located on the bends, will be integrated soon in the orbit feedback loops. 4905 hours have been delivered in 2010 to the beamlines with an availability of 96.3%. The user operation with the maximum current of 500 mA is foreseen to start by fall 2011, after the completion of the radiation safety tests of the beamlines.

THPC149

Development of PrFeB Cryogenic Undulator (CPMU) at SOLEIL

3233

C. Benabderrahmane, P. Berteaud, N. Béchu, L. Chapuis, M.-E. Couprie, J.P. Daguerre, J.-M. Filhol, C. Herbeaux, A. Lestrade, M. Louvet, J.L. Marlats, K. Tavakoli, M. Valléau, D. Zerbib
SOLEIL, Gif-sur-Yvette, France

A R&D programme for the construction of a 2 m long 18 mm period CPMU is under progress at SOLEIL. The cryogenic undulator will provide photons in the region of 1.4 to 30 keV. It will be installed in the next few months on the long straight section (SDL13) of the storage ring, and could be used later on to produce photons for the NANOSCOPIUM beamline. The use of PrFeB which features a 1.35 T remanence (Br) at room temperature enables to increase the peak magnetic field at 5.5 mm minimum gap, from 1.04 T at room temperature to 1.15 T at a cryogenic temperature of 77 K. Praseodymium was chosen instead of Neodymium magnetic material, because it is more resistant against the appearance of the Spin Reorientation Transition. Different corrections were performed first at room temperature to adjust the phase error, the electron trajectory and to reduce the multipolar components. The mounting inside the vacuum chamber enables the fitting of a dedicated magnetic measurement bench to check the magnetic performance of the undulator at low temperature. The results of the magnetic measurements at low temperature and the comparison with the measurement at room temperature are reported.

THPC150

Review of Insertion Device Dedicated to HIgh Energy Photons at SOLEIL

3236

O. Marcouillé, C. Benabderrahmane, P. Berteaud, F. Briquez, L. Chapuis, M.-E. Couprie, T.K. El Ajjouri, F. Marteau, M. Valléau, J. Vétéran
SOLEIL, Gif-sur-Yvette, France

Producing high energy photons between 10 keV and 70 keV is a challenging topic in a medium energy storage ring. It requires up-to-date measurement techniques and specific Insertion Device (ID) technologies to produce high magnetic fields and short periods. SOLEIL (2.75 GeV) has designed and built eight conventional in-vacuum hybrid undulators operating at high radiation harmonics and also one small gap multipole wiggler to produce high magnetic field. The construction has been progressively improved by the choice of new magnetic materials of better quality and higher magnetization, additional correction techniques and mechanical changes. A 2-m long full scale cryogenic undulator made of PrFeB and vanadium permendur has been built, measured, corrected and is to be tested on the beam. An additional wiggler dedicated for Slicing experiments has been designed. The required magnetic field is high enough to also consider the ID as a good candidate for the production of hard X-ray photons. This paper presents the ID dedicated for the high energy photons and their spectral performances.

THPC151

The 65 mm Period Electromagnetic/Permanent Magnets Helical Undulator at SOLEIL

3239

F. Marteau, P. Berteaud, F. Bouvet, L. Chapuis, M.-E. Couprie, J.P. Daguerre, T.K. El Ajjouri, J.-M. Filhol, P. Lebasque, J.L. Marlats, A. Mary, K. Tavakoli
SOLEIL, Gif-sur-Yvette, France

SOLEIL prepares a new 65 mm period Electromagnetic/Permanent Magnets Helical Undulator (EMPHU), with a rapid switching at 5 Hz of the polarization required for dichroïsm experiments. The vertical field Bz is produced by coils fed by a fast switching power supply (designed and built in house), with a maximum current of 350 A and a polarity switching time shorter than 100 ms. The coils consist of 25 stacked copper layers shaped by water jet cutting. The current flows in 16 layers and 9 of them are cooled with thermal drain to a water piping. 4 additional power supplies feed 2 types of correction coils for the dynamic compensation of the field integrals, besides the ones for the termination. 1.28 T remanence NdFeB permanent magnets generate the horizontal field Bx. Peak Bz and Bx in the helical configuration reach 0.24 T at 14.7 mm minimum gap. Thermal modelling and measurements aim at keeping the magnet temperature constant. The static magnetic configuration was optimised using the ID_Builder software and the trajectory were checked for insuring a good reproducibility of the photon beam pointing when sweeping from one helicity to the other.

THPC152

Measurements of SOLEIL Insertion Devices using Pulsed Wire Method

3242

M. Valléau, C. Benabderrahmane, M.-E. Couprie, O. Marcouillé, F. Marteau, J. Vétéran
SOLEIL, Gif-sur-Yvette, France

SOLEIL permanent magnets insertion devices are usually measured with a Hall probe in order to evaluate the electron angular deflexion, their deviation and the optical phase error, a figure of merit related to the quality of the insertion device radiation. A pulsed wire bench is developed at SOLEIL for reducing the measurement time of an undulator and for providing a measurement method without lateral access. A current pulse injected in a stretched wire inside the magnetic field area generates acoustic wave. The wire motion is detected by optical sensors whose signals are proportional to the local integral value. The signal-to-noise ratio of this method is often reduced due to several effects such as electronic noise, external and wire vibrations. However, following some hardware optimization it was possible to increase it up to almost 26 dB, making the method accurate and reproducible in order to realize efficient corrections. Measurements of first and second integral performed with Pulse wire, with Hall probe and with the electron beam are compared on three different types of insertions: an U18 in-vacuum cryogenic undulator, a HU60 APPLE-II undulator and a WSV50 in-vacuum wiggler.