Progress towards the ERLP at Daresbury

Neil Bliss ESLS Workshop 15 - 16th Nov 04

Progress towards the ERLP at Daresbury

Neil Bliss

ESLS Workshop 15-16th November 2004


Contents

• Aims & Objectives of Project

• Timescales

• Collaborations

• Technical priorities

• Progress on Design & Construction

• Funding Opportunities

• Acknowledgements


Research, Development and Design

• Timescale April 03 – March 07• £14 million• Project Manager – Professor Elaine Seddon• Project Sponsor – Professor Colin Whitehouse, Director of Daresbury Laboratory

Four years of funding for the research, development and design work needed to address the key challenges of the 4GLS facility.

establish and operate 4GLS ERL prototype facility

undertake 4GLS underpinning physics studies

collaborate where other international efforts are directed at addressing problems of common interest

Aims: To enable the development of core skills and to gain ‘hands on’ experience to meet the 4GLS challenge


4GLS: The Vision

A world-leading synchrotron radiation facility to enable internationally outstanding science

by the ‘low-energy’ community in the UK

4GLS combines, for the first time, superconducting ERL, SR and FEL technology in a multi-source facility


Timescales

Case prepared for 4GLS Investment Decision


Funded*

Not yet funded

Timescales

Case prepared for 4GLS Investment Decision


• Answer key questions defining layout Dec 04– FEL layout options– 180 Bend– Beamline layouts

• Engineering Layouts start Jan 05• Further questions resolved Mar 05

– Switching– High current operation

Timescales


• 4GLS User Meeting April 05• First review of costs July 05• Detailed design for CDR April 05 to Nov

05• Revise Layout & Costs Dec 05• Produce Project Plan Jan 06• Produce CDR Document Feb 06• CDR Published end Feb 06• TDR to follow …

Timescales


In October John Wood signed MoUs with SLAC Jefferson Laboratory

The agreements cover a broad spectrum of activities from accelerator studies through fast pulse diagnostics to scientific exploitation of FEL sources.

Already have links with DESYLinks with FZ Rossendorf (ELBE) developinge2v

Collaborations


Technical Priorities for the ERL Prototype

1. Demonstrate energy recovery

2. Operate a superconducting linac

3. Produce and maintain bright electron bunches from a photo-gun

4. Produce short electron bunches from a compressor

5. Demonstrate energy recovery with an insertion device that significantly disrupts the electron beam

6. Have an FEL activity that is suitable for the synchronisation needs

7. Produce simultaneous photon pulses from a laser and a photon source of the ERL Prototype that are synchronised at or below the 1ps level


Parameters

• Nominal Gun Energy 350keV• Booster Energy Gain 8 MeV• Injector Energy 8.35 MeV• Linac Energy Gain 26.65 MeV• Circulating Beam Energy 35 MeV• Linac RF Frequency 1.3GHz• Bunch Duty Factor-1 16• Bunch Repetition Rate 81.25 MHz• Bunch Spacing 12.3 nS• Max Bunch Charge 80 pC• Particles per Bunch 5 E+08


Parameters at long Pulse mode

• Average Current 13 mA• Peak Current 6.5 mA• Average Power at Injector Energy108.6 W• Average Power at Full Energy 455 W• Peak Power at Injector Energy 54.3 kW• Peak Power at Full Energy 227.5 kW


ERLP Building Layout


Accelerator Layout


1

2

3

4

Booster to FEL

Elegant

FEL to Dump

Elegant

FEL Interaction

GENESIS

8.35/35MeV 35/8.35 MeV250k particles

Gun to Booster

ASTRA

0 to 8.35MeV250k particles 250k particles106 particles

First case of modelling an ERL together with a FEL and energy recovery

Start-to-end Simulations


ERLP output


ERL Prototype Photoinjector


LASER ROOM

ACCELERATORHALL

Shield wall

Optical Table

DC GunBased on

Jlab design

Commercial 500kV(350kV)8mA DC Power Supply(Glassman Europe)Power supply and gun enveloped by 0.8 Bar SF6 environment

Booster Cavity

Laser Beam Transport System

ERL Prototype Photoinjector


Cathode material Cs:GaAs

Electron bunch charge 80 pC

Bunch length 20 ps

Bunch repetition rate 81.25 MHz

Pulse train length 1 bunch and 20-100 s

Pulse train repetition rate Single shot and 1-20 Hz

Cathode efficiency 1 %

Laser wavelength 532 nm

Laser pulse energy at cathode

20 nJ

Average power at cathode <4 mW

Pulse length <20 ps

Beam diameter at cathode 2-6 mm (FWHM)

Nd:Vanadate Laser material

- -

- -

81.25 MHz Pulse repetition rate

- -

Cw mode-locked Pulse train rep. rate

- -

1064 / 532 nm Laser wavelength

61.5 nJ532nm output energy per

pulse

5 W Average power

7 ps Pulse length (FWHM)

0.6 mm Beam diameter output

Laser

The commercial solutionRequirements


Laser System Layout

Cho

pper

f=1750mm

laserf=610mm

2

f=762mm

f=793mm1102mm

1846.06mm

1802mm 290

.94

mm

Shu

tterP

ocke

lscel

lA

naly

ser

Diagnostics

Dia

gnos

tics

Cho

pper

f=1750mm

laserf=610mm

2

f=762mm

f=793mm1102mm

1846.06mm

1802mm 290

.94

mm

Shu

tter

/2 plate

Poc

kelsc

ell

Ana

lyse

r

Diagnostics

Dia

gnos

tics

Plan View Schematic of Optical Table Layout


2-6 mm beam size on the cathode

Gaussian on day 1

Flat top in later phase

Beam Transport System


ChopperChopper• To generate 60-140 s long trains of pulses

with 100 Hz repetition rate• To decrease the thermal load on the electro-optic

modulator (Pockels cell)

Mechanical shutterMechanical shutter• To select pulsetrains with 1-20 Hz• To decrease the thermal load on the Pockels cell

PockelsPockels cellcell•To clean up the rising and falling edges•To select down to single pulse

Pulse Structure


Light Box

Cathode

Vacuum Valve

Light Box


Gun Assembly

XHV

Ceramic

Cathode SF6Vessel removed

Cathode ball

Stem

Electrons

laser

Anode Plate


Ceramic

• Controlled Resistivity Ceramic – WESGO

• Surface Resistivity 105 -1013 W/sq• Surface Resistivity 1010 -1012 W/sq• Dielectric Strength 27 DC kV/mm• Colour Black• Material Al970CD• Delivery End of Jan 05• Cost £36K


Buncher Cavity

FZ Rossendorf DesignBuncher cavity being manufactured by Vacuum Generators UK, available for testing end of November 04.

70 mm

• Single Cell• 1.3 GHz• Longitudinal bunch

compression• No Acceleration• Zero-phase crossing angle


Booster & Linac Modules


Liquid helium vessel 2 K

Helium transfer line

Accelerating module

100 W Shield at 80 K

FZ Rossendorf Module




ELBE Type Cryostat with dual Tesla Linac Sections

Order placed in March 04 – on Accel

• FZ Rossendorf Module – two TESLA cavities

• Energy Gain 26.65 MeV

• Independent control of Qext

• Independent control of cavity phase

• Delivery of module 1 (booster) due 28/11/05

• Delivery of module 2 (linac) due 6/3/06

• Cost £1.7m

Tesla 9-cell cavity


Cryogenics

StaticDuty

Dynamic

Duty

TotalDuty

Time Averaged

TOTAL SYSTEM

Cavities 45.1 161.3 206.4 litres / hour

Main transfer lines 24.4 24.4 litres / hour

Other equipment 12.8 12.8 litres / hour

Total consumption 82.3 161.3 243.6 109 litres / hour

1650 974 2620 litres / day


Cryogenics

Order placed on Linde (TCF50)

• Delivery due in May 05

• Cost £1.26m


Inductive Output Tubes

• Higher frequency than standard IOT

– High Frequency IOT – 1.3GHz & 1.5GHz

• Cathode - grid transit time effects

– Grid gap required – 0.125mm

– Standard IOT – 0.18mm

– Grid process capability

– Cathode – grid gap setting

• Integral output cavity

– Ability to set / maintain the required frequency

RF to be supplied by IOTs that are being developed by the RF group in collaboration with e2v

50KV DC Power supply commissionedIOT’s available Now


IOT 116LS Test Results

Frequency 1.2986 1.2986 1.2986 GHzBeam Voltage 24.9 24.9 27.7 kVBeam Current 0.91 0.84 1.1 AGrid Voltage -104 -122 -109 VDrive Power 220 260 260 WOutput Power 12.4 12.4 16.3 kW-1dB bandwidth 2.4 2.4 3.6 MHz-3dB bandwidth 4.4 4.8 5.7 MHzEfficiency 54.7 59.3 53.5 %Gain 17.5 16.8 18.0 dB


Magnets

• Being procured on a Performance Based Specification

• Preliminary modelling has taken place with FEA codes; minimal engineering design

• Field quality is responsibility of supplier. Magnets accepted on basis of magnetic measurements

• Large quantity (40%) of the magnets being loaned from JLAB

• 66 magnets in total required, 39 to procure• 9 Dipoles• 26 Quadrupoles• 4 Sextupoles

• + 28 H/V Correctors• Tender Notice published OJEU 16th September• Return Date 3rd November• Bids received from 3 companies• Currently evaluating bids• Contract cost approx. £350K• Two delivery stages planned

– Stage 1 (TL2) end of May 05– Stage 2 (Arcs & Dump) end of July 05

Dipole A Good field:+/- 1x10-4 over +/- 33mm

Quad D Good gradient:+/- 1x10-3 over +/- 42.5mm


ERLP Layout

New Magnets (39 off) JLAB Magnets (27 off)


Power Converter Ratings & Performance

Family Numberof

magnets

RatedVoltage(Volts)

RatedCurrent(Amps)

Dipole A 3 20 10

Dipole B 4 6.3 40

Dipole C 2 5.75 40

Dipole D 6 20 75

Dipole E 4 7.5 90

Quad A 8 8 5

Quad B/C 16 18 10

Quad D 12 12 10

Quad E 3 16.6 20

Quad F 4 12 5

Sext A 4 12 5

Total 66 Plus 28 Bipolar Corrector power converters.

• Quantity - All 66 magnets are individually powered.

• Unipolar – Dipoles fitted with changeover circuit.

• Interface – Remotely operated with analogue control.

• Standardisation – Magnet ratings matched to reduce converter spares.

• Operating range - 0 to 100% rated O/P current.

• Stability - ± 100 ppm long term, measured at ± 20ppm over 4 hrs.

• Reproducibility - ± 200 ppm over a 24 hr period.

• Resolution – 16 bit (15ppm)


Beam position monitor (¾ )- beam position- longitudinal bunch structure- current measurement- beam loss reference

measurement.Unit A: H& V Slits/ pepper pot/

viewer- beam size directly - emittance measurement. Transverse kicker cavity- longitudinal characterisation of

the beam.Analyser magnet- energy and energy spread

Units B: Viewer and vertical slit- emittance - image the beam- energy spread measurement.Unit C/E: Viewers- energy spread measurements- emittance measurements at the

position of the first accelerating cell

Faraday Cup- temporal structure of the pulse- total charge in the pulse- energy and energy spread

Diagnostics Summary


Diagnostics Summary

• 14 Optical Transition Radiation (OTR’s) Beam Viewers

• 3 Florescent Screens (YAG’s)• Stripline EBPM 14 locations• Button EBPM 12 locations• Faraday Cup (in TL 2)• Total Current Monitor• Electro–optic sampling monitor

OTR

Al foil

Beam impedance screen

Pneumatic operated mechanism


Stripline EBPM / Corrector coils

Section

Corrector Coils


Arc EBPM

EBPMs

Arc Dipole Magnet


Building Work Progress

• Renovation of old SF6 tanks for gaseous He

• Laser room approaching completion

• Ventilation system for control and diagnostics rooms being installed

• Rack room well advanced

• Bulk internal shielding complete (more than 2000 tonnes of concrete moved)

• Plinths for external labyrinths laid


Laser & Diagnostics Rooms


Assembly Building


Magnet Test Room


Module 1 - Transfer Line 2

Girder

Support PedestalIon Pump

Quadrupole Magnet OTR

Corrector Coil and EBPM Assembly

Dipole Magnet

Lifting Points

• Modular

• Majority of vacuum joints made in clean room

• Services can be fitted

• Modules can be built in parallel


Module 4 - Injection Chicane

Injection Chicane VesselCamera

Tube

DV Magnet DU Magnet

OTR

Ion Pump


Module 16 - Compression Chicane

Bolt on castors for use in assembly

area

Port for OTR

Compression Chicane Chamber

Dipole Magnet DWQuadrupole Magnet

Chamber Support

Magnet Support


Assembly Philosophy, Supports and Adjustment Systems

This philosophy ensures that the magnetic centres of all the magnets are accurately positioned with respect to each other.

1st position the Magnets in their modules in the assembly building.

4 survey points per magnetPosition of survey points to magnetic centre accurately known.

2nd Locate and drill pedestals in the Tower – position not critical

3rd Survey modules into position in the towerSurvey grid as global reference4 survey points per girder

Magnet Adjustment

Survey points

Girder adjustment

Pedestal


Survey Equipment

Faro Laser Tracker

Repeatability 1m +1 m /m

Accuracy 10 m + 0.8 m /m

Uncertainty ≈ 10 m /m

Portable

Robust

Spatial Analyzer Metrology Software

Error Simulations

Multiple instruments/types

Automation


± 0.05 mR/m measuring length± 0.5 mR for 150 mm long quadrupoles

Yaw

Roll± 0.2 mR

Pitch

± 2.5 mm± 0.5 mmY

± 0.5 mm± 0.1 mmTransverse X, Z

Globalwithin ± 15m

Local zonewithin ± 2.5m

ERLP Positional Tolerances

Y X

ZYaw

Pitch

Roll

Co-ordinate System


ERLP – 1st Grid Simulation

1st Simulation of proposed reference grid in SA

76 Grid reference points

40 Instrument positions

Each point measured by a minimum of 3 instruments

Faro Tracker

Grid reference points


ERLP – Simulation Results

Most points can be surveyed to within +/- 50 m

Worst point within +/- 82 m

Instruments reference multiple points, worst Instrument position +/-13 m


Vacuum Vessels Arc

Dipole chambers

OTR chambers

Straight chambers

Taper transition

Bellows

OTR chambers


Rectangular to Circular Transition

Taper

Arc rectangular aperture80 mm hor. X 42 mm vert.

Bellows circular cross-sectionDiameter 50 mm - NO RF SCREENING


General Considerations

• Build up of contaminant layers on optically-reflecting surfaces.

• Cryodeposition of contaminant layers on the cold surfaces of superconducting cavities

• System particles by:

– using low particle production components

– particle control measures during preparation and installation.

To minimise the following:


Class 100 (ISO 5) Clean Room

LASAIR II Model 310/510Particle sizing sensitivities from 0.3 – 25 microns

Clean Room Monitoring

LASAIR II Model 110Particle sizing sensitivities from 0.1 – 5 microns

Vacuum Chamber Monitoring


ERLP Vacuum Regions

Region Pressure/mbar Pumps Diagnostic

Gun 1x10-11 IONP/NEG EXT/RGA

TL1 1x10-10 IONP/NEG IMG/RGA

Booster 1x10-10 Cryo/IONP IMG/RGA

TL2/BTS 5x10-8 IONP PENG/RGA

Linac 1x10-10 Cryo/IONP IMG/RGA

OCFM 5x10-8 IONP* PENG*

OCBM 5x10-8 IONP* PENG*


Example Pressure Profile

•Numerical Method Using MathCad and/or Molflow to Generate Pressure Profiles

–Input data includes dimensions and vacuum surface performance


Control System - Options

• SRS control system (based on CERN ISOLDE)

• Very familiar design and techniques

• Re-use of some hardware and software from SRS

• Not supported outside of DL

• EPICS – DL work on DIAMOND

• Specifically designed for accelerator control systems

• free and widely supported (used at JLAB)

• Can re-use designs and systems developed for Diamond

• SCADA (several systems)

• Quick and easy to get going

• Expensive licensing

• More suited to process control applications & standalone systems


Control System - Overview

•The control system will use EPICS, VME and PC Consoles

•Re-use designs already developed for SRS and Diamond

•Limit control and monitoring of devices to a minimum

•Ensure maximum flexibility and low development cost

•Combine general control system with stand-alone and proprietary systems where necessary

ClientOperator Interface

LAN

ServerInput Output Controllers

Equipment Being Controlled


EU funding to help support the underpinning physics studies…

EUROFEL, FP6 Design Studies Call, awarded, EU 9 M single pan European FEL bid on underpinning technical activities (top in Peer Review)

North West Science Fund…. £4 M outline bid successful: detailed bid submitted Sept 17th

Hope to hear in Dec 2004

Current Funding Opportunities


NW Science Fund bid: £4.036M

If funded:

• 3 year programme starting 2005

• X-ray generation by Thomson scattering

• Laser-SR synergy

• THz and tissue culture facility

Other things were considered but were rejected – disruption to ERLP too great


Acknowledgments

• All the team working on the Project• 4GLS IAC• Collaborators

e-mail [email protected]://www.4gls.ac.uk

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Progress towards the ERLP at Daresbury

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