Bruno Muratori (for the EMMA team)

STFC, Daresbury Laboratory

EMMA commissioning

02/09/08

Overview

• What is commissioning ?– Preparing machine for beam

• set-up DAQ & controls & hardware• set-up diagnostic devices required

– Getting beam into the machine & where you want it– Making sure all desired properties are achieved

• for the bunch (full characterisation etc.)• for the machine (e.g. dispersion-free sections)

– Set-up machine for particular experiments– Need as many simulations of the machine as possible !

I. Gun commissioning - complete (December 2007)

II. First energy recovery- will start now (September 2008) !- all procedures are ready (in Wiki)- online modelling (Mathematica based), being

currently developed- get the energy recovery without FEL first

III. Machine tuning - fine beam tuning - phase space manipulation to achieve minimal bunch

length - full beam characterisation - EO bunch length measurements

ALICE commissioning (1)

IV. Energy recovery with FEL- first light from FEL- energy recovery of FEL disrupted beam - commissioning complete

V. ALICE exploitation - CBS experiments- tomography with space charge (in EMMA injection line)- other experiments (e.g. linac transfer matrices measurement)- preparations for EMMA commissioning

ALICE commissioning (2)

ALICE schematic

LINAC

BOO

STER

GU

N

SOL-01

H&V-01

H&V-06BPM-01

BUNCHERYAG-01

SOL-02

H&V-02 BPM-02

Q-01

YAG-02 Q-02

BPM-03

H&V-03 Q-03

Q-04

YAG-03

DIP-01

Q-05

DIP-02

YAG-??

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-01BPM-01H&V-01

ST1

OTR-02 DIP-01DIP-02

DIP-03Q-01

OTR-03

BPM-02H&V-02

Q-02 Q-03 Q-04

OTR-04

BPM-01DIP-01

BPM-02SEXT-01

OTR-01

ST1 ARC1

ARC1

Q-01

V-01

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-03DIP-02

BPM-03Q-03

V-02

Q-04

OTR-02SEXT-02BPM-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-01Q-01

Q-02Q-03

OTR-01

DMP

1 m

Note: scale is for guidance only

ERLP SCHEMATIC DIAGRAM

v.0.2 (15/06/2006)extracted from AO-180/10078/E

• Need similar schematic for EMMA injection line, ring and extraction line (shall be enormously more detailed … !)

Injection Line Commissioning (1)

• I Prepare ALICE as Injector for EMMA– Set required beam energy (e.g. 10 MeV)– Beam characterisation

• Bunch length / Charge / Emittance / Energy spread / other ?

– Hardware commissioning– Controls & online model commissioning

• These should be as comprehensive as possible (within reason)

– DAS commissioning

Injection Line Commissioning (2)

Set initial charge at 1 pC• II Thread beam through injector line

– Cancel dispersion in diagnostic straight– Steering: use steerers & kickers to get beam to given

point & with right angle depending on energy and required septum settings

– Beam characterisation (as much as possible – as always !)

– Comparison with models wherever possible

Injection Line Commissioning (3)

• III EMMA ½ turn → extraction– Threading beam without acceleration– Threading beam with acceleration– Characterisation of beam in both cases (extraction /

diagnostic line)• IV EMMA 1 ½ turn → extraction

– Threading beam without acceleration– Threading beam with acceleration– Characterisation of beam in both cases (extraction /

diagnostic line)

Injection Line Commissioning (4)

• V EMMA 10 turn → extraction– Same as before but

• In one go ?• Step by step ? (i.e. one turn at a time)

– Characterisation of beam in all cases

Set nominal charge (q = 16 or 32 pC)• VI Repeat all of the above• VII EMMA exploitation

– Establish Orbit– Tune measurements– Aperture survey

ALICE

EMMA

ALICE quadrupoles

SRS quadrupoles

New quadrupoles

Faraday Cup

Screen

last dispersivesection

Diagnostics:injection line

Diagnostics – injection line (1)

• OTR Screen in ALICE before extraction dipole• BPMs @ entrance of every dipole in injection line• Straight ahead Faraday cup to measure charge &

energy spread• OTR screen in dogleg for bunch length & energy

measurement• Tomography section: 60 degrees phase advance per

screen with three screens for projected transverse emittance measurements

Diagnostics – injection line (2)

• Last dispersive section:– OTR screen & vertical slit in middle of first section

together with– OTR screen in final section for energy and energy

spread measurements– Vertical steerers for position & angle before ring (to

be used with kickers for steering)– BPM at entrance of EMMA ring for position before

entering

Online Modelling (1)

• Build on ALICE experience– Gun commissioning

• Script to run ASTRA for comparisons / predictions– Injection line

• Run GPT for space charge calculations in ALICE• Script to run ELEGANT / other for remainder of

ALICE– ALICE ring

• Script to run ELEGANT / GENESIS / other codes for lasing etc.

Online Modelling (2)

• Create model of ALICE to EMMA injector line in GPT– Run this model both on & off line for comparisons /

predictions• Create S2E model for all of EMMA in GPT

– Run with field maps & misalignments for comparisons / predictions

– Run all the way to spectrometer & dump in the EMMA extraction line

• Compare this with ZGOUBI models & FFEMMAG models wherever possible

Online Modelling (3)• Ring optics – what things may look like

courtesy S. Machida

Online Modelling (4)• Injection orbit and optics - what things may look like

Set septum and kicker strength

See orbit and optics of incoming beam

courtesy S. Machida

Injection Septum 65°

Kicker

Kicker

Cavities x 19

Extraction Septum 70°

Kicker

Kicker

Screen

Wire Scanner

Wall Current Monitor

Wire Scanner

Screen

BPM x 82

D Quadrupole x 42F Quadrupole x 42

16 Vertical Correctors

IOT Racks (3)

Waveguide distribution

EMMA Ring

KickerPowerSupplies

SeptumPowerSupply

SeptumPowerSupply

KickerPowerSupplies

Establishing the orbit (1)• Look at Beam Position Monitor (BPM) one by one from the

injection point (not symmetric → not straightforward)• Adjust initial beam position (x,x’,y,y’) as well as Quad

current and position

BPM

Establishing the orbit (2)

• Double focusing lattice (QF and QD)• Bend fields are created by shifting quadrupoles

QFQD

Linear slide

• 4 knobs– QF and QD strength– QF and QD position

(horizontally)

• 4 parameters to fit

– Qx and Qy

– TOF shape and offset

ERLP

EMMA

SRS quadrupoles

New quadrupoles

TD Cavity

spectrometer dipoleDiagnostics:

extraction line

Diagnostic linedeflecting cavity tomography EO

spectrometer

NEW DIAGNOSTICS BEAMLINE LAYOUTSpectrometer BPM @ dipole entranceScreenFaraday Cup

E-O Monitor

Screen x 3Tomography Section

Wall Current Monitor

BPM & Valve

SRS Quadrupoles x 6

New Quadrupoles x 4

ALICE

New Dipoles (43°) & BPMs at dipole entrance

Current measurement Longitudinal profile

Position measurement

New Quadrupoles x 4

Screen& Vert. Slit

Emittance measurement

Extracted momentum

Location for Transverse Deflecting Cavity(NOT IN BUDGET)

Screen

Measurements in diagnostic line

• Energy– First dipole & spectrometer at end with OTRs

• Emittance– Quadrupole scans & tomography 60° phase

advance / screen– Equivalent set-up in injection line for comparisons

• Bunch length– EO monitor downstream of tomography– No profile information

Measurements with TDC

• Slice emittance & transverse profiles given by

– knowledge of R12 from TDC to screen

– horizontal dimension on screen gives slice emittance– vertical dimension gives bunch length

• Slice energy spread given by– streaked beam and spectrometer

12 sind sR 01 11 12''01 21 22

xx R R

xx R R

Experiments on EMMA

• Cross different large resonances• Measurement of time of flight

– Change frequency until no synchrotron oscillations– Frequency then translates into TOF– Hence find minimum of TOF

• Relationship of TOF to lattice parameters / tune– Tune vs. energy

• Study variation of all parameters to lattice properties• Interpretation of BPM readings

– Not all identical & only symmetry every other cell– Important to model all BPM readings → GPT / other

Aperture survey

• Phase space at injection• Scan aperture in phase space with a pencil beam• See S. Tzenov’s talk for more details

• When is normalized acceptance is 3 mm rad ?• Explore acceptance at all energies• Should also be modelled with FFEMMAG, GPT & others• To be done at all energies from 10 to 20 MeV

x’

/

x

/

pencil beam

Conclusions / Discussion

• Commissioning for EMMA will be a lengthy procedure !• As many models as possible are required for all aspects

of the machine– At all energies– For all lattices

• These may be far from

perfect but should give

insight into the trend or

pattern of beam behaviour e.g. ALICE solenoid scan• Online models should also be done where possible &

necessary

0

5

10

15

20

300 320 340 360 380 400

SQRT (XY)FWHM (Astra)

SQ

RT

(X

Y),

mm

B1, G

SOL-01 scanBeam size (FWHM) on YAG "A"Q = 54pC (#712)