Target Baseline

1
Target Baseline

• IDS-NF Plenary
• CERN
• March 23-24, 2009

2
The Neutrino Factory Target Concept
3
Path toward a Target System Design
4
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
The Hg Jet Nozzle

• Nozzle performance
• The Issue

6
The Jet/Beam Dump Interaction
T. Davonne, RAL
7
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
Eruption of mercury pool surface due to 24GeV
proton beam
Autodyne simulationSplash following pulse of
20Terra protons
9
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
Containment Design Requirements

• Material compatible with high-field magnets
• 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
• 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
Toward a Target Prototype

• Esatablish a coherent, engineered design concept
• Design and test an improved nozzle
• Design an Hg handling system
• Design and test a CW Hg delivery system
• Design, fabricate and beam test a target
  prototype

12
Hg Jet Target Geometry
Previous results Radius 5mm, ?beam 67mrad
Tcrossing 33mrad
13
The Target/Collection System

• Count all the pions and muons that cross the
  transverse plane at z50m.
• For this analysis we select all pions and muons
  with 40 lt KElt 180 MeV.

14
50GeV Beam-Mesons at 50m
40MeVltKElt180MeV
15
Mesons at 50m
Mesons/Proton
Mesons/Proton normalized to beam power
Fixed Parameters R5mm Beam Angle67mrad
Jet/Beam 33mrad
ISS Results reported April, 2006
16
Vary the Target Radius
17
Optimized Target Radius 2 to 100 GeV
18
Beam Angle and Jet/Beam Crossing Angle
Crossing Angle
Beam Angle
19
Mars14 vs Mars15 Comparison
20
Normalized to Beam Power
21
Normalized to Peak
22
Summary

• Peak meson production efficiency for a Neutrino
  Factory Hg Target system occurs in the region of
  6 to 8 GeV
• At 20 GeV we have a 25 loss in efficiency
• At 40 GeV we have a 45 loss in efficiency
• At 80 GeV we have a 50 loss in efficiency

23
Backup Slides
24
Optimized Target Parameters
Target Radius
Beam Angle
Beam/Jet Crossing angle
25
Optimized Target Parameters
Proton Beam Angle
Target Radius
26
Beam/Jet Crossing Angle
27
Meson Production Normalized to Beam Power
28
Process mesons through Cooling
Consider mesons within acceptance of e- 30p mm
and eL 150p mm after cooling
180 MeV
29
Compare 50m to Post-Cooling
30
Step 1 Vary the Target Radius
Rmax0.48cm
31
Proton Driver Parameters

• Proton driver power 4 MW
• Proton driver repetition rate 50 Hz
• Proton energy around 10 GeV
• 3 proton bunches in train
• 1.71013 protons per bunch at 10 GeV
• Bunch length 13 ns
• Train length at least 200 µs

32
Optimizing Soft-pion Production
33
Step 2 Vary the Beam Angle
?beam89mrad
34
Step 3 Vary the Beam/Jet Crossing Angle
?crossing25mrad
35
Post-cooling 30p Acceptance