IPAC2011 - List of Authors (Lestrade, A.)

Paper	Title	Page
TUPC068	SOLEIL Beam Orbit Stability Improvements	1156
	N. Hubert, Y.-M. Abiven, F. Blache, F. Briquez, L. Cassinari, J.-C. Denard, J.-F. Lamarre, P. Lebasque, N. Leclercq, A. Lestrade, L.S. Nadolski SOLEIL, Gif-sur-Yvette, France
	The electron beam orbit stability has been significantly improved at synchrotron SOLEIL. Low frequency noise sources have been localized and identified: the fans installed on the storage ring to cool down the ceramic chambers of the kickers, shaker and FCT, were slightly wobbling the electron beam orbit at 46, 50, 54 and 10⁸ Hz. The localization method and the solutions that will allow reducing the noise from 0.8 μm RMS down to 0.3 μm are presented. Besides, a new 160 m long beamline, NANOSCOPIUM, is being installed on a canted straight section. Its photon beam position stability requirements are very tight calling for the following improvements: addition of 2 more BPMs and fast correctors in the orbit feedback loops, new INVAR stands for BPM and XBPM integrating Hydrostatic Level System sensors. The paper is also discussing other projects that did or will contribute to improving the beam orbit stability: installation of 145 temperature sensors on the storage ring, a new analog feedforward correction system for insertion devices, and the use of the bending magnet X-BPM measurements in the slow and fast orbit feedback loops.

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.

Paper

Title

Page

SOLEIL Beam Orbit Stability Improvements

1156

N. Hubert, Y.-M. Abiven, F. Blache, F. Briquez, L. Cassinari, J.-C. Denard, J.-F. Lamarre, P. Lebasque, N. Leclercq, A. Lestrade, L.S. Nadolski
SOLEIL, Gif-sur-Yvette, France

The electron beam orbit stability has been significantly improved at synchrotron SOLEIL. Low frequency noise sources have been localized and identified: the fans installed on the storage ring to cool down the ceramic chambers of the kickers, shaker and FCT, were slightly wobbling the electron beam orbit at 46, 50, 54 and 10⁸ Hz. The localization method and the solutions that will allow reducing the noise from 0.8 μm RMS down to 0.3 μm are presented. Besides, a new 160 m long beamline, NANOSCOPIUM, is being installed on a canted straight section. Its photon beam position stability requirements are very tight calling for the following improvements: addition of 2 more BPMs and fast correctors in the orbit feedback loops, new INVAR stands for BPM and XBPM integrating Hydrostatic Level System sensors. The paper is also discussing other projects that did or will contribute to improving the beam orbit stability: installation of 145 temperature sensors on the storage ring, a new analog feedforward correction system for insertion devices, and the use of the bending magnet X-BPM measurements in the slow and fast orbit feedback loops.

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.