Work done in Annecy on Accelerator R&D

1. Work done in Annecy on Accelerator R&D C.Adloff, B.Bolzon, Y.Bastian, L.Bellier, L.Brunetti, F.Cadoux, G.Cougoulat, P.Y.David, N.Geffroy, C.Girard, R.Hermel, A.Jeremie, Y.Karyotakis, J.Lottin, F.Peltier, J.Prast, J.Tassan, S.Vilalte

2. 2 topics • LAViSta (Laboratories in Annecy working on Vibration and Stabilisation): • Sensor and actuator assessment • Simulations • Feedback loop • CTF3 (CLIC Test Facility 3) : • BPM • Analog electronics • Digital electronics

3. LAViSta 1.Within European funding agencies: EUROTeV and CARE Y.Karyotakis is WP leader within EUROTeV and part of EUROTeV Management 2. ATF2 : A.Jeremie is Scientific Coordinator for Annecy within the French ATF2 collaboration

4. LAViSta LAViSta studies mechanical active stabilisation within a given frequency range (0,1Hz to 100Hz) where the beam repetition rate doesn’t allow beam-based feedback : • Sensors measuring magnet displacements • Feedback to decide on an action • Actuators for displacement correction • Simulations => for EUROTeV : simulation of whole system => for ATF-2: simulation of FF magnets

5. LAViSta : simulations Measures excitation Beam vibrates due to excitation =>Verificfation of the numerical model Data and simulation comparison => The model can then be used for predicitions

6. LAViSta generation of pink noise with loudspeaker Free end Some acoustic peaks above 100Hz have an amplitude comparable to the low frequency peaks

7. Feedback algorithm to reject resonances on a 2,5m long quadrupole prototype actuator accelerometers Simultaneous feedback on 3 peaks

8. LAViSta For ATF-2 Estimation of usefulness of CERN stabilisation table for Final Focus set-up at ATF-2 : Simulation of Final Focus magnets Weight and size constraints: do the foreseen Final Focus magnets and monitors fit on the table? Installation on site

9. LAViSta Financial resources (2006):

10. LAViSta ☺ vibration measurement material ☺simulation know-how ☺feedback validated on simple cases ☹ still to make proof of principle in the nanometre range • Within ATF2, test in real experimental environment • For ILC, the needed criteria can be reached if the right cryogenic instrumentation can be used • For CLIC, still need work!

11. Beams diagnostics electronicsfor the CTF3 Combiner Ring Louis Bellier, Richard Hermel, Yannis Karyotakis, Julie Prast, Jean Tassan, Sébastien Vilalte LAPP - Annecy

12. Reminder : Beam parameters in the Combiner Ring The Combiner Ring performs a second compression step on the bunch trains. Beam current range : 1A - 35 A Beam pulse length : 140 ns – 1500 ns Repetition rate : 5Hz - 50 Hz

13. Beam Position Monitor (BPM) • Inductive sensor delivered by INFN: • Works as a transformer excited by the beam. • 4 electrodes located on top and bottom. • Max horizontal deviation : +/- 15 mm • Max vertical deviation : +/- 10 mm • Expected resolution : 50 m • Total length : 24 cm. Signal amplitude depends on the beam position and the beam current.

14. Existing Electronics Read out errors due to common mode noise. Expensive coaxial cables. From A. Stella (LNF/INFN)

15. LAPP’s involvement • Equip the Frascati BPM of the Combiner Ring. • Analog part : Final electronics by next summer. • From electrode voltages A, B, C,D, summing and 2 differences are generated. • Digital part : Complete study for the end of 2006 • Analog to digital conversion • Local calculations • Data transmission / reception through optical fibers. • Shaping for the acquisition part. Full compatibility with the existing electronics.

16. BPM Analog part B C D A Front-end part Optical Trans Digital part Σ ∆ v ∆ h 100m Back-end part Acquisition board LAPP’s Proposal • Front-end: • Shaping • ADC, FPGA • Data transmission • Radhard electronics • Acquisition: • Data reception • FPGA • VME interface • Commercial electronics

17. Analog electronics (1) • Horizontal and vertical deviations : • VV = (A+B) - (C+D) • VH = (B+C) - (A-D) • Sum proportional to the beam current : • V = A+B+C+D • A similar electronics has been developed by M. Gasior for the Linac part, but with different beam parameters. • Combiner Ring requirements : • 5 decades of BW required : • 10 kHz - 100 MHz • High output voltage range delivered by BPM (for 35 A current beam): • 0V - 40 V on the electrodes • 0V- 88 V for the sum. From Marek Gasior (CERN)

18. Analog electronics (2) • A first study was made at LAPP last winter. • First prototypes produced and successfully tested at LAPP. • Will be tested in the beam, on BPM during next weeks (on the delay loop and linac). • Full production awaited for this summer to equip the combiner ring this fall.

19. Digital electronics (1) • 3 inputs : • Horizontal deviation : VV = (A+B) - (C+D) • Vertical deviation : VH = (B+C) - (A-D) • Sum proportional to the beam current : V = A+B+C+D • Requirements on the analog to digital conversion : • 12 bits to keep a resolution of 50 m on the 30 mm maximum deviation and a SNR of 7. • Min sampling @ 200 MHz = 2 * max Analog bandwidth. =>12 bit, 200 MSPS ADC reach the limits of current techno. • Use of SAM Analog Memories • Developed by CEA for the HESS 2 astrophysics experiment • Circular buffer of 256 points (1024 points next fall) • Sampling at 200 MHz. • Dead time between 2 bunches used to digitalized data. • Allow to use slower ADC • 14 bits, 800kSPS ADC to digitalize data.

20. Digital Electronics (2) • Use of FPGA to read the ADC • Formatting of raw data and BPM tagging. • Possibility of local calculations (filtering, average current, average position, maximal deviations, feedback calculations, ...) • Interface between the ADC and the output part. • Data transmission through optical fibers • Fast and high security point to point connection between the front end and the acquisition. • Transmission of BPM data. • Transceivers allow both data transmission and reception. This can be used for the online configuration and the calibration. • SPECS boards can also be used to output data. • Developed by LAL for LHCB experiment. • 10 Mbits /s on RJ 45 cables, up to 100 m long. • Reduce development time (Front end and acquisition part). • 10 kRad tolerant electronics.

21. ADC 14 VΣ SAM clk clk1 ADC 14 ∆ v SAM clk clk1 ADC 14 ∆ h SAM clk clk1 SPECS Mezzanine board FPGA RJ 45 // Bus clk OR clk1 5 5 Optical Out Ser/Des 16 clk = 200MHz clk1 = 800kHz Digital Electronics (3)

22. Digital Electronics (4) • Design of the architecture OK. • End of CAD foreseen for next June. • Tested prototype for next fall. • Production for the beginning of 2007 to fully equip the combiner ring. • Possibility to equip also CLEX and the transfer line of CTF3.