Susan Smith (diagnostics).ppt -...

ALICE Diagnostics

Accelerators and Lasers In Combined

Experiments

Susan Smith ERL09Susan Smith ERL09

Susan Smith

Daresbury Laboratory

Contents

• Quick Review of ALICE Diagnostics

– Extended injector line

• ALICE to EMMA transfer line

• EMMA eBPM

Other ALICE diagnostics etc.

Susan Smith ERL09

• Other ALICE diagnostics etc.– EO

– Feedback

– Synchronisation

– Beam arrival monitor

• Initial emittance measurement

ALICE schematic

LINAC

Q-01

YAG-02Q-02

BPM-03

H&V-03 Q-03

Q-04

YAG-03

DIP-01

Q-05

DIP-02

YAG-05 FCUP-01

BPM-04H&V-04

Q-06Q-07

Q-08Q-09

DIP-3

Q-10

YAG-04

Q-11 BPM-05H&V-05

Q-12

INJECTOR

OTR-01

BPM-01H&V-01

ST1

OTR-02 DIP-01

DIP-02

DIP-03Q-01

OTR-03

BPM-02H&V-02

Q-02 Q-03 Q-04OTR-04

BPM-01 DIP-01

BPM-02 SEXT-01OTR-01

ST1 ARC1

Q-01

V-01Q-04

OTR-02

SEXT-02

BPM-05

DIP-03BPM-06

ARC 2

ST4

OTR-01Q-01 Q-02

BPM-01H&V-01

Q-03

DUMP-01

Q-04 Q-05

BPM-02H&V-02

OTR-02DIP-01 DIP-02 DIP-03

BPM-01

Q-01Q-02

Q-03OTR-01

DMP

ALICE SCHEMATIC DIAGRAM

v.0.5 (04/12/2008)extracted from AO-180/10078/G

VALV-03

VALV-01 VALV-02

SLIT

SLIT

FCUP-01

FCUP-01

D

F

D

F

F

F

F

F

F

F F

F

F

F

F

F

F

D D

D

D D

D

D D D

Susan Smith ERL09

BO

OSTER

GU

N

SOL-01 H&V-01

H&V-06

BPM-01

BUNCHER

YAG-01

SOL-02 H&V-02

BPM-02

ARC1

Q-02

BPM-03

DIP-02

BPM-04

Q-03

V-02

Q-04

OTR-02SEXT-02

BPM-05DIP-03

BPM-06

OTR-01

Q-01Q-02

BPM-01H&V-01

OTR-02

Q-03Q-04

BPM-02H&V-02DIP-01

DIP-02BPM-03V-03

OTR-03

DIP-03

DIP-04Q-05

ST 2ST 2

ARC 2 PLM-01TCM-01

BPM-04H&V-04

BPM-05H&V-05

BPM-01H&V-01

Q-06Q-07

WIGGLER

ST 3ST 3

Q-01Q-02

Q-03Q-04

OTR-01

BPM-02H&V-02

BPM-01DIP-01

BPM-02SEXT-01

OTR-01

Q-01

V-01

Q-02

BPM-03

DIP-02BPM-04

Q-03

V-02OTR-01

1 m

Note: scale is for guidance only

VALV-01

VALV-02

SLIT

F

FFFFFF

F

D

D

DDDDD

D

D

Gun to Booster

BO

OSTER

• not many beam diagnostics left here

• there is a V-slit (in YAG-01 section)

Setting buncher zero-cross phase

• Use BPM-02 for TOF measurements

• BPM phase is compared with the 1.3GHz clock

using fast scope

Susan Smith ERL09

GU

N

SOL-01

H&V-01

H&V-06BPM-01

BUNCHER

YAG-01

SOL-02

H&V-02 BPM-02Slit

Vertical

• criteria: no BPM phase shift while varying

buncher RF power

• accuracy: a few degrees

200 ps/div 500 ps/div

Diagnostics Diagnostics Diagnostics Diagnostics beamline:beamline:beamline:beamline:---- gun gun gun gun commissioningcommissioningcommissioningcommissioning

Current Current Current Current beamlinebeamlinebeamlinebeamline

Current beamline

Extended Extended Extended Extended

Extended Gun Line


Extended Extended Extended Extended beamlinebeamlinebeamlinebeamline

• Comparable final emittance in the injector

• Better control over the beam prior the booster

• Full beam characterisation

- emittance, energy spectrum, bunch length, longitudinal phase

space

• Easy buncher setup

• Beam optimisation before injecting into the booster

Advantages of the extended gun beamline

Susan Smith ERL09

• 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 )

- insertable Faraday cup (to set the bunch charge quickly)

- ion trapping devices (?)

ALICE: Injector

H&V-03 Q-03

Q-04

YAG-03

DIP-01

Q-05

DIP-02

YAG-05 FCUP-01

BPM-04H&V-04

Q-06Q-07

Q-08Q-09

DIP-3

Q-10

YAG-04

Q-11 BPM-05H&V-05

Q-12

INJECTOR

OTR-01

BPM-01H&V-01

ST1

DIP-03BPM-06

ARC 2

ST4

OTR-01Q-01 Q-02 Q-03 Q-04 Q-05

OTR-02

SLIT

D

F

F

F

F

F

F F

F

D D

D

D D D

Emittance

• slit scan

• quad scan

Slit for

energy spectrometer

Bunch charge

Susan Smith ERL09

BO

OSTER

Q-01

YAG-02Q-02

BPM-03

H&V-03 Q-03

Q-01

V-01

Q-02

BPM-03

DIP-02BPM-04

Q-03

V-02

Q-04

OTR-02

SEXT-02

BPM-05 BPM-01H&V-01

DUMP-01

BPM-02H&V-02

OTR-02DIP-01 DIP-02 DIP-03

VALV-03

VALV-01

SLIT

FCUP-01D

F

F

F

D

D

Energy spectrometer

Mean beam energy and energy spectra

Bunch length (zero-cross method)

DIP-04Q-02Q-01 OTR-03

BPM-02H&V-02

VALV-01

Q-01

Q-02

Q-03

H&V-01YAG-01

BPM-01

Q-03(ST1)

F D F D

DIP-01OTR-04Q-04

(ST1)

DIP-01

H&V-02

Q-04Q-05

Q-06 Q-07

YA

ALICE to EMMA

ALICE: Linac to Arc 1

LINAC

OTR-02 DIP-01

DIP-02

DIP-03Q-01

OTR-03

BPM-02H&V-02

Q-02 Q-03 Q-04

OTR-04

BPM-01DIP-01

BPM-02SEXT-01

Twiss parameters

Emittance

Dispersion correction

Susan Smith ERL09

DIP-04(ST1)

Q-02(ST1)

Q-01(ST1)

OTR-03 (ST1) DIP-01(AR1)

(ST1)OTR-03 OTR-04 SEXT-01OTR-01

Energy spectrometer

Energy spread/spectrum

Absolute energy

Bunch length (zero-cross)

BPM

YAG screens x 3Emittance measurement

YAG screen &vertical slit

YAG screen

YAG screen

ALICE

30°Dipole

EMMA Ring

EMMA INJECTION LINE

Energy spectrometer

Mean beam energy and energy spectra

Bunch length (zero-cross method)Energy spectrometer (with slit)

Mean beam energy

Energy spectra

Tomography section


BPM at dipole entrance

Wall Current Monitor Combined horizontal and vertical steering magnet x 4

Vertical Steering Magnet x 2

Faraday cupBeam dump

short Quads x 13

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

Prototype Coupler

RF Detector,

Susan Smith ERL09

buttons, coupler and strip line

delay cables give a 12 ns delay,

signals combined in single high

quality coax

• Detector card in rack room

outside of shielded area

– Prototype tested and moving to a

VME style card design

Clock Control and ADC

EO diagnostic & other light beamlines

CBS Unit

Laser wire: Grahame Blair : [email protected]

Susan Smith ERL09

TW laser

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...

Diagnostics and Instrumentation Dev.

Susan Smith ERL09

• 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

probe laser co-propagates with bunch (with transverse offset)

Coulomb field of

relativistic bunch

Electro-optic sampling of Coulomb field


relativistic bunch

probe laser

encodingof bunch information

into laser

decodingof 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)


accel. cav. accel. cav.gun. accel. cav.accel. cav.

FEL

bunch profile(& arrival time)

ARF, φRF

bunch profile(& arrival time)

ARF, φRF

algorithm from bunch profile to cavity

phase/amplitude machine specific

Electro-optic monitors for CSR, CTR, FEL radiation

Results obtained by going to other facilities....

• Temporary installation / short term experiments

• Full 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

Optical master clock and timing distribution

• single pulse circulating within cavity

leading solution...

require <10fs timing stability for both machine and user operation


• single pulse circulating within cavity

• pulse repetition rate set by cavity

round trip time...

• Cavity length / laser pulse train locked

to accelerator master RF

Cavity frequency and phase actively stabilised

by locking to stable RF reference...

cavity length susceptible to low frequency noise/drifts...

but.. very low noise at high frequencies

More stable than best RF oscillators

S.P. Jamison/ ALICE Stakeholders meeting, Feb. 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 Darsebury...

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

Modulation probed by pulses from

waveform at external modulatoroptical 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

25

Normalised emittance v bunch charge : slit measurements (Small and crude selection of data only ) . Period 7.

Q-scan

• Beam characterisation was not a priority in Periods 6 and 7 (up to Feb 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 ….

Susan Smith ERL09

0

5

10

15

20

0 20 40 60 80 100

Em

itta

nce

Q, pC

Q-scan• ~10mm.mrad ? : cautiously optimistic ….

Thanks

ALICE team

Steve Jamison – EO, Feedback, Synchronisation,

Beam arrival monitor

Susan Smith ERL09

Beam arrival monitor

Alex Kalinin & Rob Smith- EMMA BPMs

Yuri Saveliev for putting together some of this

talk

Susan Smith (diagnostics).ppt -...

Documents

Transcript of Susan Smith (diagnostics).ppt -...