Presentation Transcript

1. ISIS upgrades David Findlay Head, Accelerator Division ISIS Department Rutherford Appleton Laboratory / STFC Proton Accelerators for Science and Innovation, 12–14 January 2012, FNAL

2. ISIS • World’s most productive spallation neutron source(if no longer highest pulsed beam power) • World-leading centre for research in the physical and life sciences • National and international community of >2000 scientists — ISIS has been running since 1984 • Research fields include clean energy, the environment, pharmaceuticals and health care, nanotechnology, materials engineering and IT • ~450 publications/year (~9000 total over 26 years) • MICE (Muon Ionisation Cooling Experiment)

5. High-impact publications for ILL and ISIS High-impact publications per instrument High-impact publications ÷ facility budget Average numbers of high-impact publications per year in 2008, 2009 and 2010: ISIS, 129; ILL, 162.

6. Diamond — X-rays ISIS — neutrons Rutherford Appleton Laboratory, Oxfordshire

8. ISIS from air

10. ISISaccelerators • Juvenile RFQ • Venerable linac • Mature synchrotron ~0.2 MW, 50 pps • Two target stations 40 pps to TS-1 10 pps to TS-2

11. 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 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

12. 70 MeV 202 MHz 4-tank H– linac

13. 1.3–3.1 + 2.6–6.2 MHz 70–800 MeV proton synchrotron

14. ISIS TS-1 experimental hall, 20 instruments

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

16. TS-1 tungsten target (plate target)

17. TS-2 tungsten target (~solid cylinder)

18. ISIS Upgrades 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 Overlap with NF proton driver 4) Upgrade 3) + long pulse mode option Seen as one of four “big opportunities” for STFC

19. ISIS MW Upgrade Scenarios 1) Replace 70 MeV ISIS linac by new ~180 MeV linac (~0.5 MW) 2) ~3.3 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)

20. ISIS MW Upgrade Scenarios 1) Replace 70 MeV ISIS linac by new ~180 MeV linac (~0.5 MW) 2) ~3.3 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)

21. ISIS MW Upgrade Scenarios 1) Replace ISIS 70 MeV linac by new ~180 MeV linac (~0.5 MW) 2) Based on a ≈ 3.3 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) More details: John Thomason’s talk

22. Common proton driver for neutrons and neutrinos • Based on MW ISIS upgrade • with 800MeV Linac and3.2 • 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 thepower and energy • needs of theNeutrino Factory

23. Neutrino factoryon Harwell site • Extensive geological • survey data available, • but needs work to • understand implications • for deep excavation muon FFAG decay ring to Norsaq 155 m below ground • UKAEA land now • not to be • decommissioned • until at least 2040 • (unless we pay • for it!) RLA 2 RLA 1 muon linac cooling phase rotation bunching decay ring to INO 440 m below ground

24. ISIS upgrade option Proton Rep. Mean Mean Neutrons energy rate current power cf. present Linac + TS-1 refurb. TS-1 800 MeV 40 pps 200 µA 0.16 MW × 2 TS-2 800 MeV 10 pps 50 µA 0.04 MW × 1 Linac upgrade TS-1 800 MeV 47 pps 552 µA 0.44 MW × 4 TS-2 800 MeV 3 pps 48 µA 0.04 MW × 1 3.2 GeV synch. TS-3 3.2 GeV 48 pps 308 µA 0.98 MW × 6 TS-2 3.2 GeV 2 pps 13 µA 0.04 MW × 1 800 MeV ch. exch. inj. TS-3 3.2 GeV 49 pps 1177 µA 3.77 MW × 12 TS-2 3.2 GeV 1 pps 24 µA 0.08 MW × 2 TS-3 3.2 GeV 48 pps 1153 µA 3.69 MW × 12 TS-2 800 MeV 2 pps 48 µA 0.04 MW × 1 Useful neutrons scale less than linearly with power

25. ISIS upgrade option Proton Energy Range Beam °C in target energy per pulse in W diameter per pulse Linac + TS-1 refurb. TS-1 800 MeV 3.2 kJ 23 cm 6 cm 1.8 TS-2 800 MeV 3.2 kJ 23 cm 3 cm 7.3 Linac upgrade TS-1 800 MeV 9.6 kJ 23 cm 6 cm 5.4 TS-2 800 MeV 9.6 kJ 23 cm 3 cm 22 3.2 GeV synch. TS-3 3.2 GeV 20kJ 130 cm 8 cm 1.2 TS-2 3.2 GeV 20kJ 130 cm 3 cm 8.3 800 MeV ch. exch. inj. TS-3 3.2 GeV 77 kJ 130 cm 8 cm 4.4 TS-2 3.2 GeV 77 kJ 130 cm 3 cm 31 TS-3 3.2 GeV 77 kJ 130 cm 8 cm 4.4 TS-2 800 MeV 19 kJ 23 cm 3 cm 44 Beam area × range, density, specific heat — very approximate

26. Let Nf (neutrons/s) be fast neutron source strength, let P (kW) be proton beam power, let rt (cm) be characteristic dimension of fast-neutron-producing target, let  (neutrons/cm²/s) be fast flux intercepted by moderator, assume Ni (neutrons/s) to be number of neutrons useful for neutron beam line instruments, and assume volume of fast-neutron-producing target to scale with power (i.e. there is a limiting watts/cm³ for removing heat). Then, very approximately, Nf P, rt P1/3,  Nf / rt2, Ni, and so Ni P /( P1/3)2 = P1/3

27. Simple three-dimensional analytic model of heat dissipated in target

28. Activities of ISIS tungsten target removed in 2005

29. Summary • Staged set of upgrades • Lot of design work being done [other WG] • We’ll certainly upgrade TS-1 — scenario 0 • Linac upgrade (to ~0.5 MW) possible nationally • Higher powers internationally • Interested in establishing limits for solid targets

31. STFC’s four “big opportunities” • HiPER 1 • Square Kilometre Array (SKA) 2 • Free Electron Light Source • ISIS Upgrades • 1European High Power laser Energy Research facility • 23000 dishes each 15 m in diameter

32. ISIS operations Typically 180 days a year running for users Maintenance/shutdown ~1–2 weeks machine physics + run-up ~40-day cycle ~3-day machine physics Machines run ~250 days per year overall ~5/year

33. Target Upgrade TS1 Matt Fletcher Head, Design Division ISIS Department Rutherford Appleton Laboratory / STFC Proton Accelerators for Science and Innovation, 12–14 January 2012, FNAL

34. Tungsten target D2O cooled • Moderators • H2O 0.5 l Gd poison Boral decoupler • CH4 0.5 l Gd poison Boral decoupler • H2 0.8 l no poison no Cd decoupler • Beryllium (D2O cooled) reflector • 18 Neutron Beam Holes

40. MERLIN eVS MAPS SXD HET TOSCA POLARIS

41. HRPD/ENGIN-X GEM MARI PEARL SANDALS IRIS/OSIRIS/VESTA PRISMA/ROTAX/ALF LOQ SURF CRISP

42. Constraints on the design of new instruments for TS-1 • Neutron beam line heights unchanged • Avoid realigning half the instruments (costly, time consuming) • Beam lines aligned with current moderators (Except N3 - SURF which could be realigned to the bottom front moderator) • Changing a void vessel window – 1-2 year shutdown and substantial risk to future operations • Two top moderators – ambient • Making top moderators cryogenic is not practical with existing transfer lines • Two bottom moderators cryogenic

44. Void Vessel Window

45. Options for the design of new instruments for TS-1 • Moderator materials • Target, moderator and reflector geometry • Poison and decoupler materials and arrangement • Addition of pre-moderator(s) • To perform an efficient optimisation each instrument should define a quantitative metric which is representative of its performance

46. Constraints • Existing, Operating and Old (25+ years) • Cost / Benefit • Beam Input – linked to Accelerator upgrade

47. Constraints • Flight line position • Shielding to be at least the same • Reliable • Upgradeable in the future • Life of targets >5 years • Risk Low • Change suspect parts • Time • Documentation • Diagnostics • Instrumentation upgrades not part of the project

48. Constraints • Conservative approach • Known materials / cooling • Bench tested where possible • Manufacturing routes understood • Flexibility for change within moderators • Possible development moderator....

49. TS-1 tungsten target (plates)

50. Geometry and materials for MCNPX , ISIS W target #1