1. Harold G. Kirk Brookhaven National Laboratory Target Considerations for Nufact and Superbeams ISS Meeting RAL April 26, 2006

2. Harold G. Kirk Main Study Parameter Design for: 4 MW

3. Harold G. Kirk Driving Target Issues l Meson Production l Proton Beam Pulse Length l Proton Beam Structure

4. Harold G. Kirk Stephen Brook’s Analysis Pions counted at rod surface B-field ignored within rod (negligible effect) Proton beam assumed parallel l Circular parabolic distribution, rod radius 20cm 1cm Solid Tantalum Protons Pions

5. Harold G. Kirk Yield of  ± and K ± in MARS No surprises in SPL region Statistical errors small 1 kaon  1.06 muons Finer sampling

6. Harold G. Kirk The Study 2 Capture Concept Maximize Pion/Muon Production l Soft-pion Production l High Z materials l High Magnetic Field Solenoid

7. Harold G. Kirk The Study2 Target System Consider Liquid Hg Count all the pions and muons that cross the transverse plane at z=50m. For this analysis we select all pions and muons with KE< 0.35 GeV.

8. Harold G. Kirk Optimize Soft-pion Production using Hg

9. Harold G. Kirk Meson KE < 350 MeV at 50m Mesons/ProtonMesons/Proton normalized to beam power

10. Harold G. Kirk Process mesons through Cooling Consider mesons within acceptance of ε ┴ = 30π mm and ε L = 150π mm after cooling 350 MeV Use meson count with KE < 350 MeV as a figure of merit.

11. Harold G. Kirk Post-cooling 30π Acceptance

12. Harold G. Kirk Carbon Target Parameters Search

13. Harold G. Kirk Carbon Target Optimization Set R=1.25cm; tilt angle = 50 mrad; Length=60cm; Z=-40cm

14. Harold G. Kirk Proton KE Scan with Carbon Count mesons within acceptance of ε ┴ = 30π mm and ε L = 150π mm after cooling

15. Harold G. Kirk Summary of Results Compare Meson production for Hg at 24 GeV and 10 GeV Compare Meson production for C at 24 GeV and 5 GeV Compare Meson production for Hg at 10 GeV and C at 5 GeV 1.07 1.10 1.90 1.77 1.181.22

16. Harold G. Kirk Conclusion Optimum Input Proton Beam Energy for Study2a configuration with Hg: 8 to 20 GeV Superbeam proton beams energies: Mini-boone 8GeV BNL AGS 28 GeV Jpark 30 to 50 GeV Numi 60 to 120 GeV CNGS 400 GeV

17. Harold G. Kirk Driving Target Issues l Meson Production l Proton Beam Pulse Length l Proton Beam Structure

18. Harold G. Kirk Proton Beam Pulse Length Study 2a J. Gallardo, H. Kirk

19. Harold G. Kirk Conclusion Optimum Proton Beam Pulse Length for Study2a configuration: 1ns Superbeam proton beams energies: BNL AGS 28 GeV 10ns Numi 4 μs CNGS 2 x 5 μs

20. Harold G. Kirk Driving Target Issues l Meson Production l Proton Beam Pulse Length l Proton Beam Structure

21. Harold G. Kirk Protons per pulse required for 4 MW 10 Hz25 Hz50 Hz 10 GeV250 × 10 12 100 × 10 12 50 × 10 12 20 GeV125 × 10 12 50 × 10 12 25 × 10 12 Proton Beam Intensity

22. Harold G. Kirk Shock Stress Analysis N. Simos

23. Harold G. Kirk SUMMARY of Performance 1 MW/50 Hz 12.0 e+12 ppp YES 4 MW/50 Hz 48.0 e+12 ppp NO 1 MW/200 Hz 3.0 e+12 ppp YES 4 MW/200 Hz 12.0 e+12 ppp MAYBE Solid Targets

24. Harold G. Kirk 5 X 50 Proton Beam Structure Johnstone, Meot, Rees l 10 GeV Proton Beam l 50 Hz l n = 5 sub-structure => 10 x 10 12 protons (10TP) per micro-bunch l Accelerate 3 to 10 GeV with harmonic 36 structure and frequency of 13.079-13.417 MHz l Adiabatically compress to 2ns l Further compress to 1ns with f=80.5 MHz and f=201.25MHz

25. Harold G. Kirk Pulse Delivery to Target ΔT = 13 μs => 52 μs bunch structure Liquid Target ΔT = 65 μs => 260 μs bunch structure Solid Target

26. Harold G. Kirk Muon Bunch Pattern in Decay Rings. 148(133) solid/liquid 80 μ + 127(!30) 127(130) 2 of 5 interleaved 80 μˉ bunch trains of 2nd ring 80 full and 127 (or 130) empty RF buckets > 100ns intervals