Accelerator Systems of the TPS

Transcription

1 Ambient Ground Motion and Civil Engineering for Low Emittance Electron Storage Ring July 2-22, 2005, Hsinchu, Taiwan Accelerator Systems of the TPS Preinjector, Booster Synchrotron, Transfer Line, and Storage Ring Kuo-Tung Hsu July 2, 2005

2 Outline Preinjector and Booster Synchrotron Beam Transfer Line Storage Ring System Summary 2

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4 Preinjector Thermionic Gun (RF Gun is option) Two Linac sections - 00 MeV (Three linac sections 50 MeV options) Command charging modulator Solid state preamplifier + high power klystron High performance low level RF system Precision power supply Sophisticated diagnostics Max. bunch width Charge in a single bunch Energy Pulse to pulse energy stability Relative energy spread Normalized emittance (s) Single bunch purity Repetition rate Single Bunch Specifications ns <.5 nc > 00 MeV < 0.25% < 0.5% rms, (+/-.5% full width) < 50π mm mrad (both planes) < Hz (nominal), 0 Hz (maximal) 4

5 Preinjector Diagnostics Macropulse envelope FCT or Wall current monitor > 3 GHz B.W real-time oscilloscope < nsec Faraday cup ~ 00 kv beam dump ~ 00 MeV beam dump ~ 5 OTR and FS OTR with sub-mm thickness could remain in the transfer line Stripline DBPM in pulse mode Longitudinal profile and bunching CTR At energy > 50 MeV SR bending magnet Bending magnet, FS, OTR Spectrometer Emittance FS, OTR Changing quad(s) strength and measuring beam profile 5

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7 Booster Synchrotron Futures Lattice: FODO lattice Emittance: Comparable with the storage ring Location: Same tunnel as storage ring Repetitive rate: Up to 3 Hz Ramping profile is programmable 7

8 Booster Synchrotron Extraction energy [GeV] Injection energy [GeV] Circumference [m] Nature chromaticity (ξ x /ξ y ) 3 GeV [nm-rad] Damping time (τ x /τ y /τ e )[ms] Momentum compaction α RF frequency [MHz] Radiation loss 3 GeV Repetition rate [Hz] 3.0 ~ Harmonic number 832 Tune v x /v y 27. / / /25.6/ x ε = 2.7 π 0. MV, +-.3% accept. 0.4 MV τ Q ~ 2 min. 0.5 MV τ Q ~.7E6 min. 8

9 Booster Synchrotron Magnet Parameters Injection (Extraction) Injection (Extraction) ( (0.4) 7 (6.46) (m) () 0.6 (.04) 0.2 (cm) (2.2).2 (0.6) ~0.33 T 0.4~2.4 T/m (0.045) T (0.9) T 0.04 T mm 2 (HxV) 24x20 mm 2 20x20 mm 2 32x22 (32x22) mm 2 25x2 (25x6) mm B/B 0-3 G/G 5x0-3 B/B 0-3 B/B 0-3 B/B 0-3 (A) (690) 650 (4.2 k) 0 (mω) (0.54) --- (mh) (0.0026) (0.0057) --- 9

10 Booster Synchrotron Power Supply Parameters Power supply AC input Output Spec. Current Ripple (ppm) Short term Stability (ppm) Long term Stability (ppm) Flow rate (LPM) Units Dipole 3 380V 60A 200V/250A Quadrupole 3 380V 05A 200V/250A Kicker & septum pulser 3 380V Corrector 220V 3A 20V/ 20A

11 Booster Synchrotron Pulse Magnets Kickers, Septums => Solid state power supply Power Supply Switching power supply (with PSI controller?) Programmable ramping profile Diagnostics Button BPM + Digital BPM processor Stripline FCT/ICT NPCT Destructive monitor (OTR screen) Orbit Control Orbit correction and feedback is possible Control system Same as storage ring e.g. Dipole Magnet PS

12 Booster Synchrotron RF System Two Options. Adopt DORIS cavities and existing RF transmitter 2. 5 cells PETRA cavity and new/existing RF transmitter 2

13 Booster Synchrotron Quantity Beam Current NPCT, New Parametric Current Transformer, Bergoz Magnetic shielding, ma resolution Nondestructive beam position OTR, FS Commissioning 2 Nondestructive first turn beam position Digital BPM Single short mode Nondestructive turn-by-turn beam position Digital BPM Turn-by-turn mode Nondestructive closed orbit beam position Digital BPM Closed orbit mode ~ 50 Tune Stripline electrode, spectrum analyzer, digital BPM Synchronize operation with booster cycle Aperture, halo scraper Filling pattern Electrode and fast oscilloscope Transverse/Longitudinal beam property Stripline electrodes 2 Lifetime NPCT, Scraper calculate form measured beam current Beam loss Fiber type or ionization type BLM Distributed around booster ring ~ 30 Transverse profile Visible light synchrotron radiation monitor Synchronize with booster cycle 3

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15 Beam Transfer Line Booster-to-Storage Ring (BTS) Transfer Line Design in on going Linac-to-Booster (LTB) Transfer Line Design in on going 5

16 Macropulse envelope FCT or Wall current monitor < nsec 2 OTR and FS Stripline OTR with sub-mm thickness could remain in the transfer line DBPM in pulse mode several 3 Bending magnet, FS, OTR Energy spectrometer FS, OTR Changing quad(s) strength and measuring beam profile Longitudinal profile and bunching Longitudinal profile and bunching Longitudinal profile and bunching FS, OTR FS in low energy OTR at energy > 50 MeV 2 DBPM in pulse mode Wall current monitor Macropulse envelope FCT or Wall current monitor Rise time < nsec FS or OTR FS in low energy OTR at energy > 50 MeV Changing quad(s) strength and measuring beam profile 6

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18 Major Parameters of the TPS Energy (GeV) Beam current (ma) Circumference (m) Nat. emittance (nm-rad) Cell/symmetry/structure β x / β y / η x (m) LS centre RF frequency (MHz) RF voltage (MV) Harmonic number SR loss/turn, dipole (MeV) 3.0 ~ / 6 /DBA 0.59/ 9.3 / Long Straights Standard Straights Betatron tune ν x / ν y / 2.28 Synchrotron tune ν s Bunch length (mm) Dipole B/L (Tesla)/(m) Mom. comp. (α, α 2 ).72m*6 7m* / , Nat. energy spread σ E Damping time (τ x /τ y /τ e ms) Nat. chromaticity ξx / ξy / 0.5 / /

19 Pulse Magnet System Specifications of the Reference Design Septum Kicker 74.5 mard bending angle 300 usec, ~ 7000 A, 000 ppm 7.8 mard bending angle 6 µsec, ~ 5000 A, 000 ppm One turn kicker (pinger), ~ 2 µsec pulser Power Supply Technology Solid state pulser Low jitter (nsec) High amplitude stability (0-3 ) 9

20 Magnet System Magnet Parameters Quantity (deg.) (m) 0.3/0.4 / (mm) (T) (T/m) (T/m 2 ) B/B x0-4 G/G 2x0-3 S/S 5x0-3 (mm) Bds/ Bds (m)

21 Technology Power Supply Switching power supply Digital PWM (e.g. PSI regulator) Simple and homogenous interface Design criterions Same control interface for all PS (~000) Easy for maintenance High reliability Control resolution ~ 20 bit for main power supply and corrector power supply Short term stability ~ 0 ppm Long term stability ~ 00 ppm Synchronization operation of all PS 2

22 Insertion Devices Parameters Long straights.72 m x 6 (Injection, SRF, Long IDs) Standard straights 7 m x 8 EPU00 EPU70 SW60 EPU60 EPU46 IVXU28 SEPU25 SU5 (kev) (mm) By (Bx) (T).0.0 (0.77) (0.7) 0.76 (0.49) (0.58) (.7) (3.92) 2.79 (.07) (.35) 2. Length (m) (mm) (kw/mr 2 ) Hybrid Pure SC Pure Pure Hybrid SC SC 22

23 RF System Parameters Beam Energy 3 ~ 3.3 GeV RF Frequency MHz Maximum Beam Current (3 GeV) 400 ma Maximum Gap Voltage 6.4 (5) MV Maximum RF Power 720 kw CESR-III 23

24 RF System cont. Transmitter Switching power supply technology High power klystron 500 MHz solid state power amplifier is also considered as an options LLRF I/Q Control Occupy two long straight sections Easy for maintenance High reliability 24

25 NPCT, New Parametric Current Transformer, Bergoz µ NPCT ICT NPCT Single short mode Turn-by-turn mode losed orbit mode ~ 68 Tune. RF knockout (Spectrum analyzer with tracking generator) 2. Digital BPM system in tune mode (Special turn-by-turn mode). Slow, high resolution 2. Fast, moderate resolution High resolution with NFAA algorithm Frequency map analysis 2 Aperture, halo < 5 % accuracy streak camera - -. Bunch-by-bunch digitizer 2. Gated intensify CCD Camera Bunch-by-bunch, Bunch-by-bunch Lifetime NPCT Calculated value Beam loss monitor, BLM PIN diode BLM PIN-diode BLM place at Hot Spots (Moderate counting rate) ~ 00 To support various lifetime study ~ 24 pin depolarization ~0-5 precision - Imaging, Interferometer, Streak camera Transverse, longitudinal, instability,..etc. - 25

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27 Control System Available Candidates for Light Sources Propriety TLS Control System (TLS) EPICS toolkits (APS, SLS, DLS, etc.) TANGO (ESRF, Elettra, Soleil,..etc.) Three available candidates share the same hardware structure Functionality of the software are similar Plenty of hardware and software support for EPICS are available Reference design => EPICS * MODOCA (Spring-8, NewSUBARU, HiSOR) 27

28 Event System Ethernet connection to fanout modules RF Clock Generator Event Generator Ring Clock Generator Event Table Rep Rate Generator 2.5 Gbps Trigger Event Stream Timing System EVG Timing Drift Compensator TDC st Level Fanout w/o delay tuning EVR 2 nd Level Fanout w/o delay tuning 2 nd Level Fanout w/o delay tuning 2 nd Level Fanout w/o delay tuning E-Gun Trigger 8 ns resolution Event Receiver Event Receiver Event Receiver Fine Delay Trigger Output 0 psec resolution 28

29 Operation Mode e-gun : Multimode operation Single bunch Programmable length of bunch train Timing system support various injection mode Single bunch/a few bunches Multi-bunches (uniform filling) with gap Hybrid mode, Mixed mode, Camshaft mode Top-up operation 29

30 Networking High availability Adequate security scheme Fiber network Control network Timing distribution network Flexibility for future upgrade 30

31 Feedbacks Play roles of the last straw => breaks the camel's back (residues motion and instabilities) Slow orbit feedback Fast orbit feedback Feed-forward ID residue field compensation Tune correction Bunch-by-bunch feedback Transverse Longitudinal 3

32 Feedbacks Stability Requirements 24P8K, ε x =.72 nm-rad, ε y = 7.2 pm-rad Source Point σ µ σ µ σ µ σ µ.72 m Long straights m Standard straights Dipole centre Position stability ~ 0.2 µm (up to 00 Hz) Angular stability < 0. µrad 32

33 Feedbacks Slow Orbit Feedback Number of electron BPM Number of photon BPM Number of correctors Correction Algorithm Feedback Processor Sampling Rate Bandwidth Corrector maximum strength Corrector power supply stability Corrector magnets Up to 68 Optional 76 (Horizontal) and 48 (Vertical) or more SVD based algorithm General purpose processor 0 Hz < 0. Hz 000 µrad ~ 2000 µrad 0-5 ~ 0-6 sextupole 33

34 Feedbacks Fast Orbit Feedback Number of electron BPM Number of photon BPM Number of fast correctors Correction Algorithm Feedback Processor Sampling Rate Bandwidth Orbit stabilization ID Corrector maximum strength Corrector power supply stability Corrector magnets (air coil) Up to 68 Optional 48 (~ 2 * ν x ), installed at bellows or ceramic chamber (or more correctors) SVD based algorithm General purpose processor or FPGA embedded in BPM processor 4 ~ 0 KHz 50 Hz ~ 0.2 at LS (vertical, < 00 Hz) ~ µm at another place (vertical and horizontal) 50 µrad 0-4 ~ 0-6 > KHz, 3db BW 34

35 Feedbacks Bunch-by-bunch Feedback Transverse instabilities: Resistive wall instability Ion related instability Resonance mode of cavity like structure Mastered by increasing the chromaticity and/or active feedbacks The active transverse feedback can relax on chromaticity and increase the dynamic aperture Longitudinal Instabilities: Longitudinal Coupled Bunch Instabilities (LCBI) driven by cavity like Higher Order Modes (HOM) for I beam > threshold current Mastered by active feedbacks 35

36 Feedbacks Bunch-by-bunch Feedback Bunch Phase or Transverse Oscillation Detector Support: Transverse feedback, Longitudinal feedback, & Various diagnostics are also supported Beam Position Monitor Feedback Processor (FPGA Based) Back-End Electronics or Power Amplifier Transverse Kicker Longitudinal Kicker 36

37 Stability Issues Measures to maintain long term stability Ground settlement and diffusion Environment control => Sophisticated (routine) girder alignment scheme => Beam based alignment => Precision environment control Measures to keep short-term stability Carefully designed girder Carefully designed cooling water channel, air flow Carefully control of impedance budget Orbit feedback Bunch-by-bunch feedback 37

38 Summary Adopt up-to-date and mature technology to design the system Innovation are still possible for various subsystems Various measures to ensure beam stability Thoroughly ground motion investigation Reduce ground motion is one of the important goal of civil engineering design Good environmental control Carefully design of various technical systems Sophisticated feedback system Reliability of the accelerator system is a key design issues 38