ALICE iagnostics Accelerators and Lasers In Combined Experiments Susan Smith aresbury Laboratory
Contents Quick Review of ALICE iagnostics Extended injector line ALICE to EMMA transfer line EMMA ebpm Other ALICE diagnostics etc. EO eedback Synchronisation Beam arrival monitor Initial emittance measurement
ALICE schematic ALICE SCHEMATIC IAGRAM v.0.5 (04/12/2008) extracted from AO-180/10078/G YAG-05 CUP-01 GUN SLIT VALV-02 H&V-06 VALV-01 SOL-01 H&V-01 SLIT IP-01 IP-02 Q-05 YAG-03 Q-04 H&V-03 Q-03 SLIT BPM-03 Q-02 YAG-02 Q-01 VALV-03 BOOSTER BPM-02 SOL-02 H&V-02 YAG-01 BUNCHER BPM-01 IP-02 Q-02 V-01 BPM-04 H&V-04 Q-09 Q-06Q-07 Q-08 IP-3 ARC 2 BPM-06 IP-03 V-02 Q-03 BPM-04 BPM-03 Q-01 ST4 BPM-05 SEXT-02 OTR-02 Q-04 OTR-01 SEXT-01 BPM-02 IP-01 BPM-01 ARC 2 OTR-01 Q-01 Q-02 Q-10 Q-03 Q-04 Q-05 BPM-02 H&V-02 OTR-01 ST 3 Q-04 INJECTOR Q-11 BPM-05 H&V-05 YAG-04 Q-12 ST1 BPM-01 H&V-01 OTR-01 BPM-01 OTR-02 H&V-01 BPM-02 IP-01 IP-02 IP-03 H&V-02 UMP-01 CUP-01 VALV-01 Q-03 BPM-01 H&V-01 Q-02 Q-01 WIGGLER Q-07 Q-06 ST 3 ST 2 BPM-05 TCM-01 H&V-05 PLM-01 LINAC 1 m Note: scale is for guidance only BPM-03 V-03 IP-03 BPM-04 Q-05 IP-04 H&V-04 OTR-03 IP-02 VALV-02 IP-01 OTR-02 BPM-02 H&V-02 IP-01 IP-03 IP-02 Q-01 Q-04 Q-03 BPM-02 H&V-02 OTR-03 BPM-01 Q-01 MP Q-02 Q-03 OTR-01 OTR-02 ST1 OTR-04 Q-02 Q-03 Q-04 BPM-01 IP-01 CUP-01 BPM-01 H&V-01 OTR-01 Q-02 Q-01 ST 2 BPM-02 ARC1 SEXT-01 OTR-01 ARC1 Q-01 V-01 Q-02 BPM-03 IP-02 BPM-04 Q-03 V-02 Q-04 OTR-02 SEXT-02 BPM-05 IP-03 BPM-06
Gun to Booster not many beam diagnostics left here there is a V-slit (in YAG-01 section) Slit Vertical H&V-06 H&V-01 H&V-02 BPM-01 SOL-01 BPM-02 SOL-02 YAG-01 BUNCHER BOOSTER Setting buncher zero-cross phase Use BPM-02 for TO measurements BPM phase is compared with the 1.3GHz clock using fast scope criteria: no BPM phase shift while varying buncher R power accuracy: a few degrees GUN 200 ps/div 500 ps/div
Extended Gun Line iagnostics Current beamline:- gun commissioning Extended beamline
Advantages of the extended gun beamline Comparable final emittance in the injector Better control over the beam prior the booster ull beam characterisation -emittance, energy spectrum, bunch length, longitudinal phase space Easy buncher setup Beam optimisation before injecting into the booster Optimise beam quality better compared to a short gun BL Ability to introduce additional tools - small aperture (to propagate low current beam (~1pC) while the injector is set to full bunch charge (~80pC) -large aperture (to cut out bad outer part of the beam ) -insertablearaday cup (to set the bunch charge quickly) -ion trapping devices (?)
ALICE: Injector Slit for energy spectrometer Emittance slit scan quad scan SLIT VALV-03 BOOSTER SLIT IP-01 IP-02 Q-05 YAG-03 Q-04 H&V-03 Q-03 BPM-03 Q-02 YAG-02 Q-01 IP-02 BPM-03 YAG-05 BPM-04 H&V-04 ARC 2 V-02 Q-03 BPM-04 CUP-01 Q-09 Q-06Q-07 Q-08 IP-3 BPM-06 IP-03 BPM-05 SEXT-02 OTR-02 Q-04 Energy spectrometer Bunch charge Q-10 INJECTOR Q-11 BPM-05 ST4 H&V-05 YAG-04 Q-12 OTR-01 Q-01 Q-02 Q-03 Q-04 Q-05 BPM-01 H&V-01 UMP-01 Q-02 Mean beam energy and energy spectra V-01 Bunch length (zero-cross method) Q-01 OTR-02 BPM-02 IP-01 IP-02 IP-03 H&V-02 ST1 BPM-01 H&V-01 OTR-01 CUP-01 VALV-01
ALICE: Linac to Arc 1 Twiss parameters Emittance ispersion correction ALICE to EMMA H&V-01 YAG-01 IP-01 Q-04 Q-06 Q-05 Q-07 BPM-01 H&V-02 Q-03 Q-02 Y LINAC OTR-02 IP-01 IP-03 IP-02 Q-01 Q-01 BPM-02 VALV-01 H&V-02 Q-02 Q-03 Q-04 BPM-02 H&V-02 BPM-01 IP-01 BPM-02 Q-03 Q-04 OTR-04 OTR-03 Q-02 IP-04 (ST1) OTR-04 (ST1) IP-01 SEXT-01 (ST1) (ST1) (AR1) OTR-01 Q-01 (ST1) Energy spectrometer Energy spread/spectrum Absolute energy Bunch length (zero-cross)
EMMA INJECTION LINE Energy spectrometer (with slit) Mean beam energy Energy spectra Energy spectrometer Mean beam energy and energy spectra Bunch length (zero-cross method) YAG screen ALICE 30 ipole BPM EMMA Ring YAG screen YAG screen &vertical slit Tomography section YAG screens x 3 Emittance measurement short Quads x 13 Vertical Steering Magnet x 2 Wall Current Monitor araday cup Combined horizontal and vertical steering magnet x 4 BPM at dipole entrance Beam dump
EMMA Electron Beam Position Monitors The BPM electronics system has to deliver 50 µm resolution over a large aperture @ 32 pc Locally mounted coupler cards Amplifies signals from opposite buttons, coupler and strip line delay cables give a 12 ns delay, signals combined in single high quality coax etector card in rack room outside of shielded area Prototype tested and moving to a VME style card design Prototype Coupler R etector, Clock Control and AC
EO diagnostic & other light beamlines CBS Unit Laser wire: Grahame Blair : g.blair@rhul.ac.uk TW laser
iagnostics and Instrumentation ev. EO longitudinal (temporal) profile monitors Improve capabilities beyond our demonstrations platform for rapid testing of new concepts move proven capability into realm of realistic accelerator technology (NLS) Beam arrival monitors test bed for fibre-laser driven BAMs... develop lower charge (<200pC) systems necessary for NLS develop peak-current BAMs (necessary for NLS?) Timing and synchronisation (sub picosecond) testing of long term reliability / capability of laser based clocks and timing distribution environmental impacts on timing/sync system
Electro-optic sampling of Coulomb field probe laser co-propagates with bunch (with transverse offset) Coulomb field of relativistic bunch probe laser encoding of bunch information into laser decoding of information from laser pulse thanks to S. Jamison
Real-time, non-destructive, ultrafast bunch temporal profile for feedback Would like >khz readout and processing for feedback (NLS) algorithm from bunch profile to cavity phase/amplitude machine specific EL gun. accel. cav. accel. cav. accel. cav. accel. cav. A R, φ R A R, φ R bunch profile (& arrival time) bunch profile (& arrival time)
Electro-optic monitors for CSR, CTR, EL radiation Results obtained by going to other facilities... Temporary installation / short term experiments ull capability not able to be explored This capability can be easily be reproduced on ALICE (~1 week setup time)
Timing and synchronisation Major issue in future/next-generation light sources require <10fs timing stability for both machine and user operation leading solution... Optical master clock and timing distribution single pulse circulating within cavity pulse repetition rate set by cavity round trip time... Cavity length / laser pulse train locked to accelerator master R cavity length susceptible to low frequency noise/drifts... Cavity frequency and phase actively stabilised by locking to stable R reference... but.. very low noise at high frequencies More stable than best R oscillators Susan S.P. Jamison/ Smith ERL09 ALICE Stakeholders Susan Smith meeting, ERL09 eb. 2009
Optical clocks and fibre distrubution technology Robustness & reliability Potential Integration into accelerator timing system Erbium doped systems: 1.55µm; likely timing distribution system frequency doubled to 770nm => potential seed for Ti:S Ytterbium doped systems: 1030 nm phasematched with Galium Phosphide (GaP) E.O. material Yb system being built at arsebury...
Beam Arrival Monitors (BAM s) Exploiting direct link into optical timing distribution system... Button BPM electrical pick-up short (~10cm) electrical connection to external telecoms EO modulator waveform at external modulator optical probe at zero-crossing Modulation probed by pulses from timing distribution system Optical intensity beam arrival time ALICE goals... Implement timing distribution / BAM system on ALICE Examine environmental issues for timing distribution capability Extend BAM capability down to NLS charge levels (<200pC)
Emittance Beam characterisation was not a priority in Periods 6 and 7 (up to eb 2009) Very crude measurements made so far (slit & Q-scan) Both indicate emittance much larger than expected from the model No optimisation was attempted yet SOL-01 > 280G (not good for Q~10-30pC) laser beam offset? INJ optimisation ~10mm.mrad? : cautiously optimistic. 25 20 Normalised emittance v bunch charge : slit measurements (Small and crude selection of data only ). Period 7. Q-scan Emittance 15 10 5 0 0 20 40 60 80 100 Q, pc
Thanks ALICE team Steve Jamison EO, eedback, Synchronisation, Beam arrival monitor Alex Kalinin & Rob Smith-EMMA BPMs Yuri Saveliev for putting together some of this talk