1. Harold G. Kirk Brookhaven National Laboratory Target Baseline IDS-NF Plenary CERN March 23-24, 2009

2. Harold G. Kirk The Neutrino Factory Target Concept

3. Harold G. Kirk Iron Plug Proton Beam Nozzle Tube SC-1 SC-2 SC-3SC-4 SC-5 Window Mercury Drains Mercury Pool Water-cooled Tungsten Shield Mercury Jet Resistive Magnets Neutrino Factory Study 2 Target Concept ORNL/VG Mar2009 Splash Mitigator Path toward a Target System Design

4. Harold G. Kirk Alternative Collection System Another containment approach includes a shortened Hg container Drain lines exit cryostat between SC-3 and SC-4 This would trap container in the cryostat, preventing future replacement

5. Harold G. Kirk The Hg Jet Nozzle Nozzle performance: The Issue

6. Harold G. Kirk The Jet/Beam Dump Interaction T. Davonne, RAL

7. Harold G. Kirk Fluka Simulation - Energy deposition in mercury pool with 24GeV beam How much of the beam energy is absorbed in the beam dump? T. Davonne, RAL

8. Harold G. Kirk Eruption of mercury pool surface due to 24GeV proton beam Autodyne simulation Splash following pulse of 20Terra protons

9. Harold G. Kirk Splash Mitigation Study 2 assumed a particle bed of tungsten balls to minimize effects of jet entering pool Many other feasible concepts to accomplish this function Simulation/analytical studies may be useful to limit options Pool circulation and drainage locations also need to be studied Prototypic testing needed for comparison & final determination

10. Harold G. Kirk Containment Design Requirements Material compatible with high-field magnets l Must also withstand some number of full-power beam pulses with no Hg in vessel (accident scenario) Desire no replaceable components Provide support for Hg weight l ~220 liters, 3 metric tons Sloped (1°-2°) for gravity drain Overflow drain for 20m/s jet (1.6 liter/s) Vent for gas transfer

11. Harold G. Kirk Toward a Target Prototype l Esatablish a coherent, engineered design concept l Design and test an improved nozzle l Design an Hg handling system l Design and test a CW Hg delivery system l Design, fabricate and beam test a target prototype

12. Harold G. Kirk Hg Jet Target Geometry Previous results: Radius 5mm, θ beam =67mrad Θ crossing = 33mrad

13. Harold G. Kirk The Target/Collection System Count all the pions and muons that cross the transverse plane at z=50m. For this analysis we select all pions and muons with 40 < KE< 180 MeV.

14. Harold G. Kirk 50GeV Beam-Mesons at 50m 40MeV<KE<180MeV

15. Harold G. Kirk Mesons at 50m Mesons/ProtonMesons/Proton normalized to beam power ISS Results reported April, 2006 Fixed Parameters: R=5mm; Beam Angle=67mrad; Jet/Beam = 33mrad

16. Harold G. Kirk Vary the Target Radius

17. Harold G. Kirk Optimized Target Radius 2 to 100 GeV

18. Harold G. Kirk Beam Angle and Jet/Beam Crossing Angle Beam Angle Crossing Angle

19. Harold G. Kirk Mars14 vs Mars15 Comparison

20. Harold G. Kirk Normalized to Beam Power

21. Harold G. Kirk Normalized to Peak

22. Harold G. Kirk Summary l Peak meson production efficiency for a Neutrino Factory Hg Target system occurs in the region of 6 to 8 GeV l At 20 GeV we have a 25% loss in efficiency l At 40 GeV we have a 45% loss in efficiency l At 80 GeV we have a 50% loss in efficiency

23. Harold G. Kirk Backup Slides

24. Harold G. Kirk Optimized Target Parameters Target RadiusBeam Angle Beam/Jet Crossing angle

25. Harold G. Kirk Optimized Target Parameters Target Radius Proton Beam Angle

26. Harold G. Kirk Beam/Jet Crossing Angle

27. Harold G. Kirk Meson Production Normalized to Beam Power

28. Harold G. Kirk Process mesons through Cooling Consider mesons within acceptance of ε ┴ = 30π mm and ε L = 150π mm after cooling 180 MeV

29. Harold G. Kirk Compare 50m to Post-Cooling

30. Harold G. Kirk Step 1: Vary the Target Radius Rmax=0.48cm

31. Harold G. Kirk Proton Driver Parameters Proton driver power: 4 MW Proton driver repetition rate: 50 Hz Proton energy: around 10 GeV 3 proton bunches in train l 1.7×10 13 protons per bunch at 10 GeV Bunch length 1 – 3 ns Train length at least 200 μs

32. Harold G. Kirk Optimizing Soft-pion Production

33. Harold G. Kirk Step 2: Vary the Beam Angle  beam =89mrad

34. Harold G. Kirk Step 3: Vary the Beam/Jet Crossing Angle  crossing =25mrad

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