1. Proton driver front end test stand Plans and organisation for 2004–05 David Findlay ISIS Accelerator Division STVLTVS EST QVI ACCELERATORIBVS CVRANDIS VICTVM QVAERIT

2. 2 2 Why a front end test stand? Prove key elements of high power proton accelerators Applications Generic Spallation neutron sources Neutrino factories Transmutation machines Tritium generators Energy amplifiers Training / Young people / Real hardware Specific ISIS upgrades UKNF UK academic accelerator community

3. 3 3 ISIS World’s leading spallation neutron source Natural wish to stay at or near front Upgrade strategies important CCLRC funding through ASTeC UK Neutrino Factory Strong drive from UKNF community PPARC support for proton driver R&D Synergies with possible ISIS upgrades UK academic community Imperial-CCLRC joint appointment Extend university accelerator centres to protons

4. 4 4 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 MWRunning SNS 1 MWRunning soon JPARC 1 MWRunning soon ISIS 1, 2, 5 MWPlans UKNF 4 MW — a big step!Plans

5. 5 5 Proton driver front end test stand at RAL ISIS Accelerator DivisionCCLRC/ASTeC Imperial CollegePPARC Warwick UniversityPPARC CCLRC/ASTeC~£500k per year PPARC~£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

6. 6 6 Relationship with CERN test stand Formal cooperation through HIPPI Meeting last week at CERN Spreading bets on beam chopper But different CERN test stand for Linac4 then SPL Proton / H – ion sources RAL test stand more generic Differences reflect organisation’s missions

7. 7 7 RFQ Bunch + accel- erate Chopper Switch in 2 ns for ~0.1 ms LEBT Match ion source to RFQ Ion source 60 mA 2 ms Beam stop Diagnostics Transverse emittances Energy & energy spectrum Bunch width Halo Or RFQ - chopper - RFQ ?

8. 8 8 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

9. 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 Anode t/c456400 – 600 Cathode t/c501440 - 530 Body t/c416390 - 460 600°C Cathode

10. Beam chopper R&D programme — specialised hardware — fast, high voltage pulser specified and procured >1 kV rise in <2 ns

14. 14 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 / Stands Operational ~60 mA ion source available LEBT assembled Design for RFQ Specification for RF driver Proven electrical design for beam chopper Design for quadrupoles and cavities for chopper Specification of diagnostics

16. 5 m 12 19 7 6½6½ 7½7½ 2 1½1½ 6½6½ R8, existing test stand area Total area 166 m²

20. 20 Also have hardware available for subsequent three years Area in R8 is well provided Space, electricity, water, air, crane, loading bay, on ISIS controls circuit, …

21. 21 2004 – 2007 Overall scheme, design, infrastructure, specifications, some hardware £2 – 2½M 2007 – 2010 Complete scheme  £5M more — but would have world-class facility [End]

22. Ion source development rig (ISDR) at RAL

23. Experimental ion source and assembly

24. RAL beam chopper design Robust design with explicit provision for high power beam collection Slow transmission line Lumped line — thermally hardened 01010101 2 ns 8 ns Up to 100 µs

25. Close-coupled chopper module 1145 mm Slow switch Fast switch Beam Buncher cavity