ISIS, FETS and ASTeC David Findlay Head, Accelerator Division ISIS Department Rutherford 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 ~10 30 Debye unitsElectric field at 1 m: ~10 GV/m

3 Overview of talk ISIS Science programme Accelerator R&D Upgrades Front End Test Stand Rôle of ASTeC

4 But first — protons in the UK At AERE 1 /Harwell/NIRNS 2 /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 ( HP motor + 24 ton flywheel) × 2

First beam from Nimrod

17 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

18 ISIS Fundamental purpose — to investigate structure and dynamics of molecular matter Neutron sources complement light sources Neutrons: ~0.1 eV → ~1Å StructureAtomic 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

22 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 Hz 5 µC each acceleration cycle Dual harmonic RF system [Chris Prior] Targets:2 × W (Ta coated) Protons: 2 × ~100 ns pulses, ~300 ns apart Moderators:TS-1: 2 × H 2 O, 1 × liq. CH 4, 1 × liq. H 2 TS-2: 1 × liq. H 2 / solid CH 4, 1 × solid CH 4 Instruments:TS-1: 20TS-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– –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 cooling phase rotation bunching RLA 1 muon FFAG RLA 2 decay ring to Norsaq 155 m below ground decay ring to INO 440 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

37 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 stand ion source, LEBT, RFQ, diagnostics

40 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

41 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

43 Ion source and LEBT optimisation 60 mA H – beam current demonstrated Low measured emittance at high current in the FETS LEBT

44 RFQ design + manufacture RFQ cold model Weld test models under investigation at Imperial Integrated electromagnetic, thermal, fluid flow and mechanical design

45 Beam chopper Essential for all high-power proton accelerators with rings FETS chopper Two-stage for wide-band functionality Basis for ESS design

46 4 metres

47 Helical prototypePlanar prototype Re-bunching cavities

48 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”)

49 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 …

50 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 enable Nimrod  ISIS ESS designs (1990s, early 2000s) ISIS second harmonic RF upgrade TS-2 FETS ISIS Accel. Theory Group  ASTeC Intense Beams Group (IBG) — IBG still in ISIS R2 building

51 ASTeC— has enabled ISIS Happy birthday! And many happy returns! — is enabling FETS — will enable ISIS upgrades