ISIS, FETS and ASTeC

David FindlayHead, Accelerator DivisionISIS DepartmentRutherford Appleton Laboratory / STFC

ASTeC 10 Years On, Thursday 13 October 2011

ISIS, FETS, ASTeC (IBG),RAL

Electron-proton dipole

ASTeC, DL

Dipole moment ~1 C.m

~1030 Debye unitsElectric field at 1 m: ~10 GV/m

3

Overview of talk

ISISScience programmeAccelerator R&DUpgrades

Front End Test Stand

Rôle of ASTeC

4

But first — protons in the UK

At AERE1/Harwell/NIRNS2/RHEL/RAL:

Harwell synchrocyclotron (1949, 165 MeV, 1 µA)

PLA (Proton Linear Accelerator, 1959–1969)50 MeV, 3-tank — originally was to be 600 MeV

Harwell ~7 MV tandem accelerator

Harwell VEC (Variable Energy Cyclotron, 1965–1980s)

Nimrod, 7 GeV proton synchrotron (1964–1978)

ISIS, 800 MeV proton synchrotron (1984– )

1 Atomic Energy Research Establishment (1946)

2 National Institute for Research in Nuclear Science (1957)

Harwell tandem

PLA — Proton Linear Accelerator

Never built

Aimed down runway

PLA tank going into Building R12 at RAL

PLA tank in R5.1 — as part of new injector for Nimrod

Remedial work on other tanks for new injector for Nimrod

PLA tank in R5.1 — as part of injector for ISIS

Cockcroft at ground-breaking ceremony for Nimrod

Construction of Nimrod synchrotron hall

4.6 MVA alternator (+ 5100 HP motor + 24 ton flywheel) × 2

First beam from Nimrod

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ISIS

World’s most productive spallation neutron source(if no longer highest beam power)

Flagship STFC facility [Sci. Tech. Facilities Council]

Driven by UK’s high-power proton accelerators

UK has largest national neutron user community of any country

Accelerator physics at ISIS necessary for continuing operations— and also for enabling entire programmes on materials R&D

Need to plan for upgrades

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ISIS

Fundamental purpose — to investigate structure and dynamics of molecular matter

Neutron sources complement light sources

Neutrons: ~0.1 eV → ~1Å

Structure Atomic motionsParacetamol

Global challenges ISIS

Energy

Living with environmental change

Global threats to security

Ageing: Life-long health and wellbeing

Digital economy

Nanoscience: through engineering to application

Impact of ISIS science

ISIS from air

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RFQ: 665 keV H–, 4-rod, 202 MHz

Linac: 70 MeV H–, 25 mA, 202 MHz, 200 µs, 50 pps

Synchrotron: 800 MeV proton, 50 Hz5 µC each acceleration cycleDual harmonic RF system [Chris Prior]

Targets: 2 × W (Ta coated)Protons: 2 × ~100 ns pulses, ~300 ns apart

Moderators: TS-1: 2 × H2O, 1 × liq. CH4, 1 × liq. H2

TS-2: 1 × liq. H2 / solid CH4, 1 × solid CH4

Instruments: TS-1: 20 TS-2: 7 (+ 4 more now funded)

~340 staff

–35 kV H– ion source

665 keV 4-rod 202 MHz RFQ

70 MeV 202 MHz 4-tank H– linac

1.3–3.1 + 2.6–6.2 MHz 70–800 MeV proton synchrotron

Superperiods 9, 0 and 1 of 800 MeV synchrotron

EPB1 and EPB2 to TS-1 and TS-2 above synchrotron

Protons to TS-1

Protons to TS-2

ISIS TS-1 experimental hall, 20 instruments

ISIS TS-2 experimental hall, 7 instruments + 4 under way

TS-1 tungsten target, plates

TS-2 tungsten target, solid cylinder

ISIS Upgrades

4) Upgrade 3) + long pulse mode option

0) Linac and TS-1 refurbishment

1) Linac upgrade, ~0.5 MW on TS-1

2) ~3 GeV booster synchrotron: MW target

3) 800 MeV direct injection: 2–5 MW target

2) ~3 GeV RCS fed by bucket-to-bucket transfer from ISIS 800 MeV synchrotron (1MW, perhaps more)

3) Charge-exchange injection from 800 MeV linac (2 – 5 MW)

1) Replace 70 MeV ISIS linac by new ~180 MeV linac (~0.5 MW)

ISIS MW Upgrade Scenarios

ASTeC staff vital to success

• Based on MW ISIS upgrade with 800 MeV Linac and 3.2 GeV RCS

• Assumes a sharing of the beam

power at 3.2 GeV between the two facilities

• Both facilities can have the same ion source, RFQ, chopper, linac, H− injection, accumulation and acceleration to 3.2 GeV

• Requires additional RCS machine in order to meet the power and energy needs of the Neutrino Factory

Common proton driver for neutron source and neutrino factory

NF on Harwell Oxford site

muon linac

coolingphase rotationbunching

RLA 1

muonFFAG

RLA 2

decay ring to Norsaq155 m below ground

decay ring to INO440 m below ground

• UKAEA land now not to be decommissioned until at least 2040 (unless we pay for it!)

• Extensive geological survey data available, but needs work to interpret implications for deep excavation and ground water activation

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FETS — Front End Test Stand

Actually the second front end test stand at RAL

First test stand was built to test RFQ to replace ISIS Cockcroft-Walton

ISIS 665 kV Cockcroft-Walton (1984–2004)

665 keV 4-rod 202 MHz RFQ

RFQ test standion source,

LEBT, RFQ, diagnostics

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Front End Test Stand (FETS)

Key technology demonstrator for next generation of high power pulsed proton accelerators

ISIS upgrades

Neutrino factories

Future spallation neutron sources

Accelerator-driven systems

Waste transmutation

...

Only dedicated high-power proton accelerator hardware R&D project in the UK

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Key components of FETS

High-intensity, high-duty factor, H– ion source(60 mA, 2 ms, 50 pps)

Magnetic low energy beam transport (LEBT)

324 MHz 4-vane RFQ

Medium energy beam transport (MEBT)

Very high speed beam chopper

Comprehensive beam diagnostics

Collaboration — ISIS, ASTeC, Imperial College, Warwick University, ESS Bilbao consortium, Royal Holloway,[Huddersfield, UCL]

In R8 at RAL

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Ion source and LEBT optimisation

60 mA H– beam current demonstrated

Low measured emittance at high

current in the FETS LEBT

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RFQ design + manufacture

RFQ cold model

Weld test models under

investigation at Imperial

Integrated electromagnetic, thermal, fluid flow and mechanical design

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Beam chopper

Essential for all high-power proton accelerators with rings

FETS chopper

Two-stage for wide-band functionality

Basis for ESS design

464 metres

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Helical prototype Planar prototype

Re-bunching cavities

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Beam diagnostics

Already in use

Current transformers

Faraday cup

Slit-and-cup scanners for time-resolved 2D emittance

Scintillators for beam profiles

Pepper-pot for 4D phase space

Being developed

Laser photo-detachment(“laser wire”)

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At present

Cutting metal for RFQ

Increasing laser power for laser wire

Continuing ion source development

…

In future

Commission RFQ

Demonstrate high-quality beam chopping

Spin out hands-on accelerator expertise

…

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ASTeC

Re-packaging of long-held national lab. skills— larger package than in the past

Skills NINA, SRS, Nimrod, ISIS, Diamond, ...

“ASTeC” skills enabled / continue to enableNimrod ISISESS designs (1990s, early 2000s)ISIS second harmonic RF upgradeTS-2FETS

ISIS Accel. Theory Group ASTeC Intense Beams Group (IBG) — IBG still in ISIS R2 building

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ASTeC — has enabled ISIS

Happy birthday!

And many happy returns!

— is enabling FETS

— will enable ISIS upgrades