Author: Jacob, J.
Paper Title Page
MOPC004 352.2 MHz HOM Damped Normal Conducting ESRF Cavity: Design and Fabrication 68
 
  • V. Serrière, A.K. Bandyopadhyay, D. Boilot, L. Goirand, J. Jacob, B. Ogier, A. Triantafyllou
    ESRF, Grenoble, France
 
  Funding: This work, carried out within the framework of the ESRFUP project, has received research funding from the EU Seventh Framework Programme, FP7.
The ongoing ESRF upgrade included an option for an increase of the storage ring current from 200 to 300 mA, which has been tested successfully with the existing RF system. At this current level the HOM tuning of the existing five-cell copper cavities becomes extremely delicate and in view of a future reliable operation in user mode, new HOM free normal conducting cavities were developed at the ESRF. The design is based on the existing BESSY/ALBA cavity. However, several substantial modifications have been implemented and different fabrication processes elaborated to improve the design. Three operational prototypes will be delivered by three manufacturers in the coming months and will be fully tested on the ring. Although the 300 mA option has finally not been retained for the first phase of the ESRF upgrade, the aim is now to validate the new cavity design for a possible later increase in current.
 
 
MOPC005 352.2 MHz – 150 kW Solid State Amplifiers at the ESRF 71
 
  • J. Jacob, G. Gautier, M.L. Langlois, J.M. Mercier
    ESRF, Grenoble, France
 
  The ESRF has ordered seven 352.2 MHz – 150 kW Solid State Amplifiers (SSA) from the French company ELTA, with a design derived from the existing SSA developed by SOLEIL. The first four SSA will be commissioned by the end of 2011 and will be connected to the two booster cavities in Winter 2012 providing in total 600 kW in 10 Hz cycles. Thanks to anti-flicker capacitor banks with a total of 3 F in the 280 V DC power supply, up to only 350 kW will be drawn from the mains as compared to 1200 kW for the former klystron transmitter. The three remaining SSA will be received in 2012 and will feed three new single cell HOM damped cavities on the storage ring. The analysis of the market had shown that an alternative to klystrons needed to be investigated to guarantee the long term operation of the ESRF. SSA can be operated with a number of RF modules lost and are therefore intrinsically highly redundant. In parallel to the production by industry of this first batch of SSA, the ESRF is developing its own amplifier modules and proposing an alternative way to combine typically hundred RF modules using a single cavity combiner.  
 
THPC008 Touschek Lifetime and Momentum Acceptance Measurements for ESRF 2921
 
  • B. Nash, F. Ewald, L. Farvacque, J. Jacob, E. Plouviez, J.-L. Revol, K.B. Scheidt
    ESRF, Grenoble, France
 
  The Touschek lifetime of a synchrotron results from electrons scattering off one another within the bunch and subsequently being lost. We have measured the Touschek lifetime for the major operating modes of the ESRF as a function of RF voltages. This includes multibunch and few bunch filling patterns with correspondingly different chromaticity values. Through calibration of the RF voltage and measurement of the other beam parameters such as bunch length and vertical emittance, we may understand the momentum acceptance in the regime where this is determined by non-linear dynamics effects.  
 
THPC009 Performance and Upgrade of the ESRF Light Source 2924
 
  • J.-L. Revol, J.C. Biasci, J-F. B. Bouteille, J. Chavanne, F. Ewald, L. Farvacque, A. Franchi, G. Gautier, L. Goirand, M. Hahn, L. Hardy, J. Jacob, J.M. Koch, M.L. Langlois, G. Lebec, J.M. Mercier, T.P. Perron, E. Plouviez, K.B. Scheidt, V. Serrière
    ESRF, Grenoble, France
 
  The European Synchrotron Radiation Facility (ESRF) is now fully engaged in a large Upgrade Programme of its infrastructure, beamlines and X ray source. In this context, a first set of 10 insertion device straight sections are being lengthened from five to six metres; a number of them will be operated with canted undulators. The insertion devices are themselves subject to an ambitious development programme to fulfil the scientific requirements. The Radio Frequency system upgrade has started with the replacement of the booster klystron-based transmitter by high power solid state amplifiers, and the development of HOM damped cavities operating at room temperature. A completely new DC-AC orbit stabilization system using 224 BPMs and 96 orbit steerers is currently being commissioned. The upgrade is conducted while keeping, and even improving, routine performance for the user service. In particular the recent installation of new skew quadrupole power supplies allows routine operation with ultra low vertical emittance. This paper reports on the present operation performance of the source, highlighting recent developments and those still to come.