The Transverse Damping Systems for the SIS100 & SIS300 Synchrotrons at the Facility of Antiproton and Ion Research (FAIR at GSI) V.M. Zhabitsky, N. Lebedev, E. Gorbachev (JINR), U. Blell, P. Spiller (GSI) 5 th Workshop on Scientific Cooperation between German Research Centres and JINR 18 January 2005 JINR

JINR- CERN - GSI2 CERN –W.Hofle, LHC ADT Project Engineer (Damper), T.Linnecar, LHC A Project Engineer (RF), R.Louwerse, J.-F.Malo, J.Tuckmantel JINR –V.M.Zhabitsky, N.I.Lebedev, E.V.Gorbachev, A.A.Fateev, A.A.Makarov, V.A.Melnikov, S.V.Rabtsoun, V.A.Bogdanov, N.V.Pilyar, V.G.Shabratov, K.P.Sychev, M.G.Pushkin, B.G.Komarov, V.I.Koryako, V.V.Kovalev + 10 pers. JINR The LHC Transverse Damping System The LHC Transverse Damping System CERN – Russia - JINR

JINR- CERN - GSI3 Key Technologies in Accelerator: Magnets –B, Q RF System –E–E Feedback Systems –N, ε

JINR- CERN - GSI4 FAIR at GSI Highest beam intensities Brilliant beam quality Highest beam power Higher beam energies

JINR- CERN - GSI5 Bunch Bunch current Induced current Differential current Induced magnetic field Vacuum chamber Coherent Transverse Oscillation If the bunch is displaced form the centre of the vacuum chamber it will drive a differential wall current. This leads to a magnetic field, which deflects the bunch.

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JINR- CERN - GSI7 W. Hofle CERN AB/RF Example SPS (CNGS type beam, 1 batch, protons): 3 ms growth rate 0.5 ms damping time 50 + turns relative silence at injection injection with damper off damper being switched on 7 ms (300 turns) after injection Transverse Feedback (LHC Damper)

JINR- CERN - GSI8 SIS100 & SIS300 Dampers Transverse Feedback System Transverse Feedback System with a real-time digital signal processing: damping of transverse injection oscillations, feedback curing transverse coupled bunch instabilities, excitation of transverse oscillations for beam measurements and other applications. General Parameters of SIS100 & SIS300 Machine Circumference: m Beam revolution frequency: kHz Beam revolution time: μs Horizontal tune at injection: Q H =26.9 Vertical tune at injection: Q V =16.7 Energy ( 238 U): – 34 GeV/u Intensity ( 238 U 73+, 238 U 28+ ): A JINR

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JINR- CERN - GSI10 Basic Parameters damping of transverse injection oscillations –(E + β 0 cB )ds ±6.0 kV (δQ - ?) feedback curing transverse coupled bunch instabilities –(E + β 0 cB )ds ±1.3 kV Strength of the kicker: –(E + β 0 cB )ds ±9.3 kV Electric kicker (L=0.5m, Δ=10cm): U = ±1.86 kV

JINR- CERN - GSI11 Bandwidth and Frequencies f min = min|k - Q|f 0 = 0.1f 0 = 10.4 kHz f max f b /2 f max (for kicker) 1/4π σ t = 3.2 MHz ( σ t =25ns ) Bunch r.m.s. spectral frequency: = 1/2π σ t = 6.4 MHz Stability of high order harmonics - ? Sampling rate: 20MSPS Transverse emittance growth rate: –τ -1 = (4/3) f (b-1) δQ 2 –τ = 84 hours (f 0 = 104kHz; b=12-1; δQ = 0.005)

JINR- CERN - GSI12 SIS100 & SIS300 Dampers JINR

JINR- CERN - GSI13 A fragment of an assembly drawing of a vertical kicker: 1 - the vacuum tank, 2 - electrodes, 3 - ceramic rings, 4 - the fixing device of the electrode module, 5 - the high voltage connection, 6 - a plate for installation of target alignment, 7 - the higher order mode connection. High voltage on electrodes: ±1400 V Bandwidth: 10 – 3200 kHz Operating vacuum: mbar JINR Kicker

JINR- CERN - GSI14 Class of operation: AB Input amplitude: ±150 V Output amplitude: ±1400 V Bandwidth: 10 – 3200 kHz JINR Power Amplifier

JINR- CERN - GSI15 The experimental results confirm a possibility of realisation of amplifier on the basis of the circuit with parallel control (cascode), which is considered as a perspective development of the system. ascode amplifier LHC Damper: investigations of a cascode amplifier JINR

JINR- CERN - GSI16 Driver Amplifier Top viewView on transformers Front viewRear view Class of operation: A Input amplitude: ±1 V Output amplitude: ±150 V Bandwidth: 10 – 3200 kHz

JINR- CERN - GSI17 JINR Central Signal Processing Field Programmable Gate Array (FRGA) technology Clock frequency: 8f RF 20MHz Digital input signal: ±12 bit Analog output amplitude: ±1 V Signal processing resolution: 12 bit Programmable delay: μs, ++50ns Fine delay: 1 – 50ns, ++1ns (??)

JINR- CERN - GSI18 Dampers: Planned Schedule Year: Prototype Pre-production unit Prototype Pre-production unit Prototype Pre-production unit Production Series Spares Tests of the TFS at the SIS100 designconstructiontesting TFS kicker JINR amplifier CSP

JINR- CERN - GSI19 Costs Estimates Costs Estimates for 4 units: equipmentquantityprice, Beam position monitors2 Monitor electronics2 Central Signal Processing Driver amplifiers Power amplifiers Kicker16000 TOTAL COST OF 1 UNIT: Costs Estimates for 1 unit

JINR- CERN - GSI20 The Transverse Damping Systems for the SIS100 & SIS300 Synchrotrons at the Facility of Antiproton and Ion Research (FAIR at GSI) Status (November 2004): Technical proposal was prepared by: –Accelerator Development Group, Gesellschaft für Schwerionenforschung mbH Darmstadt –Laboratory of Particle Physics of the Joint Institute for Nuclear Research

JINR- CERN - GSI21 LHC Damper Transverse Feedback System Transverse Feedback System with a real-time digital signal processing: damping of transverse injection oscillations, feedback curing transverse coupled bunch instabilities, excitation of transverse oscillations for beam measurements and other applications. General LHC Parameters Machine Circumference: m Beam revolution frequency: kHz Beam revolution time: 88.9μs Horizontal tune at injection: Q H =64.28 Vertical tune at injection: Q V =59.31 JINR

JINR- CERN - GSI22 JINR The LHC Transverse Damping System The LHC Transverse Damping System CERN – Russia - JINR The Damper is in the list of the systems that must operate already for first beam injection. Therefore the schedule of construction, installation and testing the Damper in the machine must be completed before November 2006.

JINR- CERN - GSI23 LHC Damper. Layout of one transverse feedback system. There are four independent systems, one per plane (H/V) and beam. JINR JINRs obligations: 20 deflectors, 40 amplifiers.

JINR- CERN - GSI24 JINR The LHC Transverse Damping System The LHC Transverse Damping System CERN – Russia - JINR Electrostatic kicker The design stage was successfully completed at the Laboratory of Particle Physics (JINR) and its results were accepted by CERN. Modern simulation methods based on Microsim PSpice and Inventor were used. Wideband amplifiers

JINR- CERN - GSI25 The LHC Transverse Damping System Assembly of the amplifier and the kicker at the tests bench. LPP, October JINR Final amplifier design

JINR- CERN - GSI26 The LHC Transverse Damping System JINR Radiophysical characteristics of the power amplifier: 7.5 kV; 10 kHz – 10 MHz. LPP, JINR, December 2004.

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