Welcome, ISIS overview,and core accelerator activities

David FindlayHead, Accelerator DivisionISIS DepartmentRutherford Appleton Laboratory / STFC

Proton accelerator R&D at RAL, 24 March 2011

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Welcome!

Aim today:

Outline description of proton accelerator R&D at RAL

Interest in contributing?

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RAL

Spun off from UKAEA Harwell in late 1950s for nuclear and high-energy physics — PLA (50 MeV DTL, 1959–69), Nimrod (7 GeV synchrotron, 1964–78)

Then ISIS (1984– )

UK proton accelerator R&D based at RAL because UK’s proton machines have been and are at RAL — knowledge, skills, experience, hardware,

infrastructures

ASTeC Intense Beams Group + ISIS

Rutherford Appleton Laboratory, looking north-east

ISIS

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ISIS

Spallation neutron source + muons + MICEFirst neutrons 1984 (TS-1), 2008 (TS-2)World-leading in terms of science outputStructure and dynamics of molecules — physics, chemistry, materials science, geology, engineering and biology

800 MeV protons on to tungsten targets, 0.2 MWTS-1, 0.16 MW, 40 pps; TS-2, 0.04 MW, 10 pps~750 neutron experiments per year~1500 visitors/year (~5000 visits)~450 publications/year (~9000 total over 25 years)

UK: has largest neutron user community in the world

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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

Targets: 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 (+ ChipIr, 14-Mar-11)

~300 staff

View down north side of ISIS 70 MeV H– linac

Superperiods 9, 0 and 1 of the ISIS 800 MeV synchrotron

ISIS TS-1 experimental hall, 20 instruments

ISIS TS-2 experimental hall, 7 instruments (+1, 14 Mar.)

TS-1 tungsten target, plates

TS-2 tungsten target, solid cylinder

4-rod RFQ, 202 MHz0.2 MW RF pulsedtetrode

One of four drift tube linac tanks, 202 MHz4 × 2 MW RF pulsed

triodes (tetrode drivers)

RF systems at ISIS (1)

2 MW, 202 MHz RF amplifier

RF systems at ISIS (2)

10 × Thales TH116 triodes

RF systems at ISIS (3)

Ferrite-loaded RF cavity2.6–6.2 MHz (second harmonic)4 cavities on machine

Ferrite-loaded RF cavity1.3–3.1 MHz (fundamental)

6 cavities on synchrotron

~1 MW RF mean

RF systems at ISIS (4)

High-power drives and

anode power

supplies

RF systems at ISIS (5) — RF test facility (R79)

RF systems at ISIS — 6

324 MHz 2 MW klystron

324 MHz RFQ (FETS)

Ground-cutting for RAL

ISIS Cockcroft-Walton ...

... now at Cockcroft Institute

Men inside DTLs

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ISIS

An operational machine with a fixed timetable— has to run when the users want it to— problems need solving now

Complicated machine to run — needs knowledgeable and experienced accelerator staff to maintain operations sustainably [e.g. Dean Adams’ talk]

Staff cannot “just” run ISIS — they need to keep up with developments in the field, engage with similar people elsewhere, etc.

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Accelerator R&D at ISIS [ASTeC work: Chris Prior’s talk]

Need knowledgeable and experienced accelerator staff to maintain ISIS operations sustainably1

Need to enable accelerator staff to engage with similar staff elsewhere

Need to look forward to possible ISIS upgrades

Need to maintain RAL as UK centre for proton accelerator R&D

— first two not optional; R&D keeps good people

1 Big, complicated, expensive machines.

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Accelerator R&D programmes at ISIS

Front End Test Stand (FETS) [APL, DCF, JP]High-quality beams for high-power proton acceleratorsPrototype front end for upgraded ISISNot a paper accelerator — real equipment on groundEngineering and technician dimensionsStrong university involvement

R&D for high-current rings [JWGT]Until recently, ISIS world’s highest average power RCSRare opportunity for measurements

ISIS upgrade studies [JWGT]Enhanced capability for investigating structure and dynamics of molecular matter

65 keV, 60 mA, 2 ms,

50 Hz, H– ion source

3-solenoid magnetic LEBT

324 MHz, 3 MeV,

4-vane RFQ

MEBT and beam chopper

Beam diagnostics and beam dump

Laser profile measurement

Front End Test Stand

Ion source collaborations:CSNS, CERN, Culham, Oxford

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R&D for high-current rings

Beam dynamics on high-current rings

Experimental measurements on ISIS ring — valuable and scarce resource

Code development and code bench-marking

Beam diagnostics development

RF systems development (DHRF, LOI)

Collaborations with ANL, J-PARC, KEK, Oxford, SNS

Time (ms)

Beam

loss

ORBIT simulations, 600k particles,64 CPUs, 3-D space chargeSimulated beam loss: 9 %Measured beam Loss: 8 %

ISIS beam loss simulations using ORBIT

UPDATE PICTURE

EC monitor 1

EC monitor 2

Strip line beam position monitor to measure beam instabilities in ring

Damping system?

SP5

Beam diagnostics

Electron cloud monitors

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ISIS upgrade studies

Phased upgrades

0) Linac and TS-1 refurbishment

1)Linac upgrade for ~0.5 MW operations on TS-1

2)~3.3 GeV booster synchrotron — ~1 MW

3) 800 MeV direct injection to booster — 2–5 MW

4)800 MeV direct injection to booster + long pulse mode option

5)Overlap with neutrino factory

ISIS 180 MeV injection upgrade studies

pH0

H−

foil injection dipolemagnets

Injection of 4E13 protons at 180 MeV over 500 turns with painting in each plane under 3-D space charge (left)

Foil studies show 6.3 foil re-circulations per proton raising temperature to 1500°K

OPERA model of injection straight showing foil scatter product trajectories

Foil hit distribution over injection

Collaborations with CERN, Fermilab, Imperial

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Key areas of expertise at ISIS

Essentially: science and technology of proton accelerators with benefit of operational experience

Optimal application of electrical, electronic, mechanical, RF and vacuum engineering

Ability to calculate beam dynamics in detail— incl. benchmarking codes in standard andnon-standard states (e.g. coasting beams)

Design and operation of beam diagnostics devices and interpretation of the signals arising from the devices

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Key areas of expertise — cont’d

Appreciation of the practical problems posed by high-power beam stops and collimators, induction of radioactivity in machine structures, etc. — including high-power targets

State-of-the-art code development and hardware architecture for running the codes

Assessment of the implications for ISIS of facilitating other R&D programmes such as MICE

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Overall aims

Run ISIS sustainably

Prepare for ISIS upgrades

Act as centre for proton accelerator R&D in UK1

Collaborate nationally and internationally

1 E.g. build new proton machines in R8, R9, R80, ...

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