First Results from the ERL Prototype (ALICE) at Daresbury

First Results fromthe ERL Prototype

(ALICE) at DaresburyDavid Holder, on behalf of the ALICE team.

LINAC'08 Victoria, BCLINAC 08 Victoria, BC

Contents

• Introduction

• Overview of Gun Commissioning

Cryogenics Superconducting Modules & RF System• Cryogenics, Superconducting Modules & RF System Status

• Next Steps

• SummarySummary

• Credits

2

• Introduction:– New Name– ALICE & EMMA Layout

• Overview of Gun Commissioning• Cryogenics, Superconducting Modules & RF System

Status• Next Steps• Summary• Credits

3

New Name

ERLP (Energy Recovery Linac Prototype) – conceived as a prototype of an energy recovery-based 4th generation

light source...now called...

ALICE (A l t d L I C bi dALICE (Accelerators and Lasers In Combined Experiments)– An R&D facility dedicated to accelerator science and technology y gy

development;– Offering a unique combination of accelerator, laser and free-electron

laser sources;;– Enables studies of photon beam combination techniques;– Provides a suite of photon sources for scientific exploitation.

4

No, not THAT ALICE…

ALICE & EMMA Layout

• Nominal Gun Energy 350 keV

• Injector Energy 8.35 MeV

• Beam Energy 35 MeV

• RF Frequency 1.3 GHz

• Bunch Rep Rate 81.25 MHz

• Nom Bunch Charge 80 pC

• Average Current 6.5 mA( th 100 b h t i )(over the 100 µs bunch train)

5

• Introduction• Overview of Gun Commissioning

– Photoinjector– Gun Problems

G Di ti L t– Gun Diagnostic Layout– Gun Commissioning Results– Gun Commissioning Summary– Gun Commissioning Summary

• Cryogenics, Superconducting Modules & RF System StatusStatus

• Next Steps• Summary

6

• Summary• Credits

Photoinjector

Gun ceramic – major source of delay – at Daresbury (~1 year late)

Copper brazedCopper brazed joint

(Fi t l t

7

(First electrons August 2006)

Gun Problems

• High voltage breakdown problems after cathode caesiation and from braze disintegration;g ;

• Vacuum failures during bake-out of large diameter flange seals, feedthrough, valve and braze (again!);g g ( g )

• Contamination (caesium again?) and hydrocarbons;– impaired XHV conditions, field emission, halo, poor

cathode lifetime.

8

Gun Diagnostic Layout

Injector commissioned with dedicated diagnostic line (now removed):

DE

LASERTRANSVERSEKICKER

A FARADAYCUPS

CDIPOLEBUNCHER

CSOLENOID 1 SOLENOID 2

9

B

Gun Commissioning Results (1 of 3)

RMS emittance b h h

Bunch length (at 10% ofpeak value) vs.bunch charge

rad)

vs. bunch charge5

met

res)

35

40ASTRA

bunch charge

pi-m

m-m

r HorizontalVertical

3

4

1(m

icro

m

25

30

35

ASTRA

mitt

ance

(

2ng

th @

0.

15

20

RMS

em

0

1

0

10 30 50 70

Bunc

h le

0

5

10

10

0 0

10 20 30 40 50 60 70 80Bunch Charge, pC

0 10 20 30 40 50 60 70 80Bunch Charge, pC


40

Energy spread (at

25

30

35

@ 0

.1 ,

keV

TOTAL

MODEL

MODEL

gy p (10% of peak value) vs. bunch charge

15

20

25

GY

SPR

EAD

@ MODEL

5

10

15

ENER

G

COMPENSATED

Compensated =

0

5

0 10 20 30 40 50 60 70 80

BUNCH CHARGE pC

buncher ON

11

BUNCH CHARGE, pC


Beam size vs. solenoid 1 & 2 current, at Q=54 pC,compa ed to ASTRA modelcompared to ASTRA model

15

20

SQRT (XY)FWHM (Astra)

( )

5

6

7

SQRT (XY)FWHM (Astra)

10

QR

T (X

Y),

mm

3

4

5

(XY

), m

m

5

SQ

1

2

3SQ

RT

(

12

0300 320 340 360 380 400

B1, G

0200 220 240 260 280 300 320

B2, G

Gun Commissioning Summary• Results:

– The gun can now be routinely HV conditioned to 450kV;– QE above ~3% is normally achieved after cathode activations Q y

(bunch charges of well above 100pC have been achieved);– The beam was fully characterised (emittance, bunch length, etc.)

for bunch charges between 1 to 80pC;– A good agreement between the ASTRA simulations and the

experimental data was found for the bunch length and the energy spread but not for the emittance;B nch cha acte istics e e in estigated at t o diffe ent lase– Bunch characteristics were investigated at two different laser pulses of 7ps and 28ps:

• At low Q<20pC, no significant difference was observed;The importance of a smooth longitudinal laser profile for minimisation– The importance of a smooth longitudinal laser profile for minimisation of the beam emittance was demonstrated.

• Remaining gun-related issues: Ens e the absence of FE spots on the cathode

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– Ensure the absence of FE spots on the cathode;– Increase the cathode lifetime with QE >1.5%;– Resolve transverse emittance discrepancy (FE? QE non-uniformity?).

• Introduction• Overview of Gun Commissioning• Cryogenics, Superconducting Modules & RF

System Status:– Cryosystem Commissioning– Booster Module & RF Layout

Module Commissioning Results– Module Commissioning Results– Field Emission Radiation Issue– Mitigating StrategiesMitigating Strategies

• Next Steps• Summary

14


Cryosystem Commissioning• Partial system procured from Linde;• 4 K commissioning completed May 06;

SRF M d l d li A il d J l 06• SRF Module delivery April and July 06;• Problems with excessive system heat leaks (lack of

capacity) and heater failure;capacity) and heater failure;• Cryosystem output:

– Specification 118 W at 2 K with 1 mbar stability;– Measured 118 W at 2 K with ± 0.03 mbar stability in

May 07;St ti l d• Static load: – Specification < 15 W per module;– Measured 5 W for both modules (i e ~2 5 W each);

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Measured 5 W for both modules (i.e. ~2.5 W each);• System has operated successfully at 1.8 K – needs further

optimisation.

Booster (8 MeV )8 MeV

Booster Module & RF LayoutBooster (8 MeV )

Cavity 2 @ 2 9 MV/m Cavity 1 @ 4 8 MV/m350 keV8.35 MeV

8 MeV

350 keV8.35 MeVCavity 2 @ 2.9 MV/m Cavity 1 @ 4.8 MV/m InOut InOut

Circulator LoadCirculator Load

Cavity 1, 4.8 MV/mCavity 2, 2.9 MV/m

C cu ato(incl. Load)

3dB Hybrid

Circulator (incl. Load)

3dB Hybrid

Directional CouplerCPI CHK51320W

30 kW CW IOT

Directional CouplerCPI CHK51320W

30 kW CW IOT

16

E2V 116LS 16 kW CW IOT

E2V 116LS16 kW CW IOT


E2V 116LS16 kW CW IOT

Module Commissioning Results

Vertical Tests at DESY (Jul – Dec 2005)

20 8

Cavity 2

18 9

Cavity 1

Booster

20 417 1E (MV/m)

Cavity 2Cavity 1

Linac

5 x 109

20.8

5 x 109

18.9

5 x 1095 x 109Qo

20.417.1Eacc (MV/m)

7 0 x 109 @1 9 x 109 @1 3 x 109 @3 5 x 109 @Q

12.816.413.510.8Max Eacc (MV/m)

Module Acceptance Tests at Daresbury (May – Sept 2007)

7.0 x 109 @ 9.8 MV/m

1.9 x 109 @ 14.8 MV/m

1.3 x 109 @ 11 MV/m

3.5 x 109 @ 8.2 MV/m

Qo

FE QuenchRF PowerFE QuenchFE QuenchLimitation

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Field Emission Radiation Issue100

80

90 Linac Cavity 1Linac Cavity 2Power (Linac Cavity 1)Power (Linac Cavity 2)

50

60

70

n D

ose

(mS

v/hr

)

20

30

40

Rad

iatio

n

0

10

20

0.0 2.0 4.0 6.0 8.0 10.0 12.0

• At 9 MV/m (c.f. required value of 13.5), radiation i i li LLRF k i i

Gradient (MV/m)

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monitor in linac LLRF rack goes into saturation.• Predicted electronics lifetime only around 1000 hrs.

Mitigating Strategies

• Lead shielding installed around linac;• New linac module (collaborative design);• Further aggressive processing:

Over longer conditioning periods;– Over longer conditioning periods;

– Varying frequency, pulse widthy g q y, pand pulse repetition rate;

– CW conditioning (only possible at lower power levels);CW conditioning (only possible at lower power levels);

– Possibly condition the cavity when warm;

19– Introduce helium into the vacuum (risky!)

SC Module Commissioning Summary

• All 5 IOTs are successfully commissioned;• All 4 cavities show unexpected limitations due to field

i iemission;• ALICE operation at 35 MeV is still possible;• Measurements of cryogenic losses at intermediate gradients• Measurements of cryogenic losses at intermediate gradients

show significant reduction compared with vertical test results;• High levels of FE radiation measured and mitigating strategies

implemented. Maximum

measuredRequired

Cavity 1 10.8 4.8 MV/m Booster

Cavity 2 13.5 2.9 MV/m

Cavity 1 16.4 13.5 MV/mLinac

20

Cavity 1 16.4 13.5 MV/mLinac

Cavity 2 12.8 13.5 MV/m

• Introduction• Overview of Gun Commissioning• Cryogenics, Superconducting Modules & RF System

Status• Next Steps:

– Accelerator (short term)– Science Programme– Accelerator Developments

EMMA– EMMA


21

• Credits

Accelerator (short term)

• First energy recovery (Fall 2008):– Without FEL, installation planned Spring 2009;

• Fine tuning: – Injector tuning for minimum emittance;

O ti i ti f t i l b– Optimisation of energy recovery at nominal beam parameters;

– Beam diagnostics;Beam diagnostics; • Short pulse commissioning stage:

– Longitudinal dynamics, electro-optical diagnostic studies;• Energy recovery with FEL (Spring 2009):

– First light!

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– Energy recovery of a disrupted beam.• Then the fun really starts…

Science Programme

IR FEL, CBS x-ray source and terahertz radiation research programme, including pump–probe research programme with all ALICE light sources:

Terawatt laser ( 10TW 100 / 35 fs 10Hz);– Terawatt laser (~10TW, 100 / 35 fs, 10Hz);– Infrared FEL (~4µm, ~15MW peak, ~1ps, ~10mJ);– Femptosecond tunable laser;Femptosecond tunable laser;– Terahertz radiation (broadband);– CBS x-ray source (15-30keV, 107 – 108 photons/pulse, y ( , p /p ,

<1ps);– Tissue Culture Laboratory (TCL).

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Science Programme

LINACBPM 03

H&V-03 Q-03

Q-04

YAG-03

DIP-01Q-05

DIP-02YAG-??

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

ST1 ARC1

BPM-05

DIP-03BPM-06

ARC 2ST4

OTR-01Q-01 Q-02

BPM 01

Q-03 Q-04 Q-05

OTR-02

ERLP SCHEMATIC DIAGRAM

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

BOOS

TER

UN

SOL-01

H&V-01H&V-06

BPM-01BUNCHERYAG-01

SOL-02H&V-02 BPM-02

Q-01

YAG-02 Q-02BPM-03 OTR 03 SEXT 01

OTR-01

ARC1

Q-01

V-01Q-02

BPM-03

DIP-02

BPM-04

Q-03V-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-03DIP-04Q-05

ST 2ST 2ARC 2 PLM-01

TCM-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-01Q-01

V-01Q-02

BPM-03DIP-02

BPM-03Q-03V-02

Q-04OTR-02

SEXT-02BPM 05 BPM-01

H&V-01

DUMP-01

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

GU

CBSWiggler

E-BEAMCBS X-ray

Phase I

Wiggler

IR FEL IR FEL532 nm

TW Laser

Phase IIIR FEL4-6µm THz

IR FEL4-6um

Photogun

24Mobile laser

TW Laserglaser

Accelerator Developments

• Accelerator physics research:– Photocathode research and testing (upgraded load-lock

t f th d h & ti ti )system for cathode exchange & activation);– New linac module;– Re-establishment of gun diagnostic line– Re-establishment of gun diagnostic line.

• EMMA - Electron Machine with Many Applications:• EMMA Electron Machine with Many Applications:– Non-scaling fixed field alternating gradient accelerator;

Why FFAG ? Why Non Scaling ?Why FFAG ?• fast acceleration (e.g. muons)• high power beam acceleration• variable electron energy

Why Non-Scaling ?• compact beamline vacuum chamber• hence, compact magnets

25

• variable electron energy

EMMA

Applications :

• medical (oncology)

• muon acceleration

• Accelerator-Driven

Sub-critical Reactor

(ADSR)

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Status• Superconducting Module Status• Next Steps• Summary• Credits

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Summary

• Accelerator commissioning has now reached a critical stage;• ALICE has provided the UK with an opportunity to developALICE has provided the UK with an opportunity to develop

generic technologies and skills important for the delivery of advanced accelerator-driven facilities, including:

Ph t i j t SCRF i di ti h i ti– Photoinjector, SCRF, cryogenics, diagnostics, synchronisation etc.

• ALICE will provide a unique R&D facility in Europe, dedicated toALICE will provide a unique R&D facility in Europe, dedicated to accelerator science & technology development:– Offering a unique combination of accelerator, laser and free-

l t lelectron laser sources; – Enabling essential studies of beam combination techniques;– Providing a suite of photon sources for scientific exploitation

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– Providing a suite of photon sources for scientific exploitation.


Status• Superconducting Module Status• Next Steps• Summary• Credits

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Credits• The ALICE technical team:

– Controls: Brian Martlew et al.– Vacuum: Tom Weston & Keith Middleman et al.– Installation engineering: Phil Atkinson et al.Installation engineering: Phil Atkinson et al.– Mechanical engineering: Neil Bliss et al.– Electrical engineering: Steve Griffiths et al.– Diagnostics: Rob Smith et al.– FEL: Jim Clarke et al.FEL: Jim Clarke et al.– Compton Back Scatter: Gerd Preibe et al. – THz Science: Mark Surman et al.– Running, Safety: Stephen Hill et al.– Photoinjector laser: Steve Jamison & Graeme Hirst et al.Photoinjector laser: Steve Jamison & Graeme Hirst et al.– Elaine Seddon, Mike Poole and Paul Quinn

• Our international collaborators including:– J Lab (George Neil, Fay Hannon, Kevin Jordon, Carlos Hernandez-Garcia, Tom

Powers et alPowers et al.– FZD Rossendorf (Peter Michel, Frank Gabriel et al.) – Cornell (Bruce Dunham)– Stanford University (Todd Smith)

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y ( )– Institute of Semiconductor Physics, Novosibirsk (Alex Terekhov)

h k f lThanks for listening

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l dSpare slides

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Linac layoutLi (26 7 M V )27 MeVLinac (26.7 MeV )

Cavity 2 @ 12 9 MV/m Cavity 1 @ 12 9 MV/m8.35 MeV35 MeV

27 MeV

8.35 MeV35 MeVCavity 2 @ 12.9 MV/m Cavity 1 @ 12.9 MV/m InOut InOut

Cavity 2, 12.9 MV/m Cavity 1, 12.9 MV/m

Directional Coupler


Directional Coupler



Thales TH71320 kW CW IOT


Thales TH71320 kW CW IOT

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First Results from the ERL Prototype (ALICE) at Daresbury

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