Proton driver front end test standPlans and organisation for 2004–

05

David FindlayISIS Accelerator Division

STVLTVS EST QVI ACCELERATORIBVS CVRANDIS VICTVM QVAERIT

22

Why a front end test stand?

Prove key elements of high power proton accelerators

ApplicationsGeneric Spallation neutron sources Neutrino factories Transmutation machines Tritium generators Energy amplifiers Training / Young people / Real

hardwareSpecific ISIS upgrades UKNF UK academic accelerator community

33

ISISWorld’s leading spallation neutron sourceNatural wish to stay at or near frontUpgrade strategies importantCCLRC funding through ASTeC

UK Neutrino FactoryStrong drive from UKNF communityPPARC support for proton driver R&DSynergies with possible ISIS upgrades

UK academic communityImperial-CCLRC joint appointmentExtend university accelerator centres to protons

44

What’s in a front end?Ion source, LEBT, RFQ and beam chopper

Why does it matter?Where beam quality set for entire machine

What has to be tested?New, high performance ion sources, RFQs and beam choppers

ISIS 0.16/0.24 MW RunningSNS 1 MW Running soonJPARC 1 MW Running soonISIS 1, 2, 5 MW PlansUKNF 4 MW — a big step! Plans

55

Proton driver front end test stand at RAL

ISIS Accelerator Division CCLRC/ASTeCImperial College PPARCWarwick University PPARC

CCLRC/ASTeC ~£500k per yearPPARC ~£500k over three years

+ 1¾ x ½ SY/year EU (HPRI-CT-2001-50021) (~£30k/year)+ 3 x ¾ SY/year EU (HIPPI/CARE/ESGARD) (~£50k/year)

£2–2½M total

66

Relationship with CERN test stand

Formal cooperation through HIPPIMeeting last week at CERN

Spreading bets on beam chopper

But differentCERN test stand for Linac4 then SPLProton / H– ion sourcesRAL test stand more genericDifferences reflect organisation’s missions

77

RFQ

Bunch +

accel-

erate

Chopper

Switch in 2 ns

for~0.1 ms

LEBT

Match ion

source to RFQ

Ion sourc

e

60 mA

2 ms

Beam

stop

Dia

gn

osti

cs

Transverse emittancesEnergy & energy spectrumBunch widthHalo

Or RFQ - chopper - RFQ ?

88

H– ion source — Development required Based on ISIS H– ion source

LEBT — Revision of new ISIS LEBT sufficient

RFQ — Base on ISIS & ESS 4-rod RFQs ISIS RFQ designed for 10% RF duty factor cf.

ISIS 2% Most expensive item: ~1 MW RF driver

Beam chopper — Development required Based on ESS concept Not necessarily ESS frequency (280

MHz)

But need ion source, LEBT and RFQ to test beam chopper

H– ion source R&D programme — for future high power proton accelerators (e.g. for future spallation neutron sources) — × ~10 output required

1 inch

Important milestone passed

Successful thermal modelling of world leading ISIS ion source — extraction of surface temperatures

Excellent agreement between calculated and measured thermocouple temperatures

Anode

200°C

Ab initio calc. Meas.°C °C

Anode t/c 456 400 – 600Cathode t/c 501 440 - 530Body t/c 416 390 - 460

600°C Cathod

e

Beam chopper R&D programme — specialised hardware — fast, high voltage pulser specified and procured

>1 kV rise in <2 ns

A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M

Overall philosophyRF frequency? One RFQ or two? Interactions with ISIS?

Ion sourceFix Bruker Extract Power SupplyExperiments: separate Penning field, neutralisation, electrode geometryTest new geometry, higher extract potential and separate Penning field 0.4 SY, £20kFurther mods. + testsDesign, build & test ×2 larger ion source EU funding stops Dec-05 0.7 SY, £30kDesign "operational" sourceBuild "operational" source

LEBT[Pretty well blanked out by RFQ installation & commissioning work]Review performance of existing test stand LEBTMagnetic or electrostatic?Design new LEBT (MAFIA, magnet design, particle tracking, vacuum)Build new LEBT

RFQ[Pretty well blanked out by RFQ installation & commissioning work]Re-visit physics designRe-visit mechanical/thermal/vacuum designAssessment of RF driverSpecification of RF driver

Beam chopperMeasurements with Kentech pulsers — to check computer codesHigh voltage, high current MOSFET switch developmentThermal calcs. for beam dumpsRepresentative prototype meander line testRepresentative prototype lumped line testPre-production meander line testPre-production lumped line testRF cavities and quadrupoles, low level RF systems

DiagnosticsReview ISIS RFQ test stand diagnosticsDesign beam current measurement apparatusRe-use magn. spectr., gas scatt. spectr., coax. target?Specify suite of diagnostics (incl. halo m's'ment) (also beam dump)

Beam dynamicsBeam dynamics for LEBT, RFQ, chopper lineError limits for RF phase and gradient, quadrupole gradient, etc.

Infrastructure / Overall practicalitiesEstimate footprint for 2–3 MeV test stand / Clash with synch. RF area?Estimate radiation shielding incl. beam losses in RFQ, chopper)Estimate services requirements and ancillary apparatus requirementsProduce outline specification and drawing of test standExtend lead shed 0.025 SY, £50kBuild and install stands and supports

0.1 SY

1.0 SY, £50k

1.0 SY, £20k

0.3 SY, £20k0.2 SY, £50k

2.0 SY, £200k

0.2 SY, £5k0.1 SY, £5k

1.0 SY, £50k

0.1 SY, £50k

0.2 SY0.1 SY

0.1 SY, £5k

1.0 SY, £50k

0.05 SY1.25 SY, £20k

0.2 SY, £5k

0.2 SY, £15k

0.4 SY

0.05 SY0.025 SY

0.025 SY0.2 SY

0.2 SY

0.5 SY, £30k

0.5 SY, £25k

2004 2005 2006

0.2 SY

0.1 SY

0.8 SY, £50k0.4 SY, £50k

0.3 SY, £10k

2007

0.8 SY, £30k0.3 SY, £30k

Overall philosophyRF frequency? One RFQ or two? Interactions with ISIS?

Ion sourceFix Bruker Extract Power SupplyExperiments: separate Penning field, neutralisation, electrode geometryTest new geometry, higher extract potential and separate Penning fieldFurther mods. + testsDesign, build & test ×2 larger ion sourceDesign "operational" sourceBuild "operational" source

LEBT[Pretty well blanked out by RFQ installation & commissioning work]Review performance of existing test stand LEBTMagnetic or electrostatic?Design new LEBT (MAFIA, magnet design, particle tracking, vacuum)Build new LEBT

RFQ[Pretty well blanked out by RFQ installation & commissioning work]Re-visit physics designRe-visit mechanical/thermal/vacuum designAssessment of RF driverSpecification of RF driver

Beam chopperMeasurements with Kentech pulsers — to check computer codesHigh voltage, high current MOSFET switch developmentThermal calcs. for beam dumpsRepresentative prototype meander line testRepresentative prototype lumped line testPre-production meander line testPre-production lumped line testRF cavities and quadrupoles, low level RF systems

DiagnosticsReview ISIS RFQ test stand diagnosticsDesign beam current measurement apparatusRe-use magn. spectr., gas scatt. spectr., coax. target?Specify suite of diagnostics (incl. halo m's'ment) (also beam dump)

Beam dynamicsBeam dynamics for LEBT, RFQ, chopper lineError limits for RF phase and gradient, quadrupole gradient, etc.

Infrastructure / Overall practicalitiesEstimate footprint for 2–3 MeV test stand / Clash with synch. RF area?Estimate radiation shielding incl. beam losses in RFQ, chopper)Estimate services requirements and ancillary apparatus requirementsProduce outline specification and drawing of test standExtend lead shedBuild and install stands and supports

SY £k SY £k SY £k

0.200

0.300 300.800 300.400 20

0.500 300.700 300.100 7 0.200 13

0.200 50

0.1000.025 0.025

1.000 16 0.250 40.667 67 1.333 133

0.133 3 0.067 20.100 50.100 3 0.100 3

0.100 5

0.800 500.267 33 0.133 170.100 3 0.100 7

1.000 500.500 25 0.500 25

1.000 500.500 25

0.500 10 0.500 10

0.0500.0250.019 0.006

0.200

0.109 0.146 0.1460.100 0.100

0.2000.050 0.050

0.1000.200 150.025 50

0.100 50SY £k

3.534 170 6.156 332 5.235 368 14.9 870

2006–07

Total

2004–05 2005–06

Resources available

SY £k SY £k SY £k

Clarke-Gayther, Mike 1.00 1.00 1.00Faircloth, Dan 0.50 0.50 0.50Findlay, David 0.10 0.10 0.10HIPPI engineering 0.70 0.70 0.70 Assumed FTEs payable by €464k/2 over 3 years

Letchford, Alan 0.20 0.40 0.40Whitehead, Mark 0.25 0.25 0.25

Long, Ken 0.10 0.10 0.10Joint IC-RAL lecturer 0.20 0.40 0.40 50% on RAL work starting Oct-04

Post-doc. (IC) 0.25 1.00 1.00Half a post-doc. (IC) 0.50 0.50Mechanical engineer (IC) 0.25 0.75 0.75RF/Electrical engineer (IC) 0.75 0.75Half a post-doc. (Warwick) 0.25 0.25

3.55 6.70 6.70ASTeC/CCLRC 200 300 400 Hope to get more money as time goes on

Cf. 3.53 170 6.16 332 5.24 368 Requirements from first sheet

Additional resources available for these three years and beyondItem WorthDanfysik arc driver 12 Total of £49k (in three orders) for four

Bruker pulser 50Selection of 500 l/s TMPs 50 Bought ~2 years ago

Stand 5Gas scatt. spectr. 25Magnetic spectr. 251 pair emittance scanners 35 3 pairs cost £105k

Data acq. for emitt. scan. 15 Reasonable guess

Odds and ends 33250

2004–05 2005–06 2006–07

1414

At end of three years, i.e. by March 2007, expect to have

Dedicated area (in R8 (probably))Lead shed (shield against RFQ X-rays)Support structure / StandsOperational ~60 mA ion source availableLEBT assembledDesign for RFQSpecification for RF driverProven electrical design for beam chopperDesign for quadrupoles and cavities for chopperSpecification of diagnostics

5 m

12

19

76½

7½

2

1½

6½

R8, existing test stand area

Total area 166 m²

2020

Also have hardware available for subsequent three years

Danfysik arc driver 12Bruker pulser 50Selection of 500 l/s TMPs 50Stand 5Gas scatt. spectr. 25Magnetic spectr. 251 pair emittance scanners 35Data acq. for emitt. scan. 15Odds and ends 33

250

Area in R8 is well providedSpace, electricity, water, air, crane, loading bay, on ISIS controls circuit, …

2121

2004–2007

Overall scheme, design, infrastructure, specifications, some hardware

£2–2½M

2007–2010

Complete scheme

£5M more — but would have world-class facility

[End]

Ion source development rig (ISDR) at RAL

Experimental ion source and assembly

RAL beam chopper design

Robust design with explicit provision for high power beam collection

Slow transmission line

Lumped line — thermally hardened

0

1

0

12 ns 8

ns

Up to 100 µs

Close-coupled chopper module

1145 mm

Slow switch

Fast switch

Beam

Buncher cavity

Buncher cavity