Harold G. KirkBrookhaven National Laboratory

Target Baseline

IDS-NF Plenary

CERN March 23-24, 2009

Harold G. Kirk

The Neutrino Factory Target Concept

Harold G. Kirk

IronPlug

ProtonBeam

NozzleTube

SC-1SC-2 SC-3 SC-4

SC-5Window

MercuryDrains

MercuryPool

Water-cooledTungsten ShieldMercury

Jet

ResistiveMagnets

Neutrino Factory Study 2 Target Concept

ORNL/VGMar2009

SplashMitigator

Path toward a Target System Design

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

Harold G. Kirk

The Hg Jet Nozzle

Nozzle performance:

The Issue

Harold G. Kirk

The Jet/Beam Dump Interaction

T. Davonne, RAL

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

Harold G. Kirk

Eruption of mercury pool surface due to 24GeV proton beam

Autodyne simulationSplash following pulse of 20Terra protons

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

Harold G. Kirk

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

Harold G. Kirk

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

Harold G. Kirk

Hg Jet Target Geometry

Previous results: Radius 5mm, θbeam =67mrad Θcrossing = 33mrad

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.

Harold G. Kirk

50GeV Beam-Mesons at 50m

40MeV<KE<180MeV

Harold G. Kirk

Mesons at 50m

Mesons/Proton Mesons/Proton normalized to beam power

ISS Results reported April, 2006

Fixed Parameters: R=5mm; Beam Angle=67mrad; Jet/Beam = 33mrad

Harold G. Kirk

Vary the Target Radius

Harold G. Kirk

Optimized Target Radius 2 to 100 GeV

Harold G. Kirk

Beam Angle and Jet/Beam Crossing Angle

Beam Angle Crossing Angle

Harold G. Kirk

Mars14 vs Mars15 Comparison

0 20 40 60 80 1000

20000

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Mes

ons

Proton Kinetic Energy, GeV

MARS15 MARS14

Harold G. Kirk

Normalized to Beam Power

Harold G. Kirk

Normalized to Peak

Harold G. Kirk

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

Harold G. Kirk

Backup Slides

Harold G. Kirk

Optimized Target Parameters

Target Radius Beam Angle

Beam/Jet Crossing angle

Harold G. Kirk

Optimized Target Parameters

Target Radius Proton Beam Angle

Harold G. Kirk

Beam/Jet Crossing Angle

!

Harold G. Kirk

Meson Production Normalized to Beam Power

!

Harold G. Kirk

Process mesons through Cooling

Consider mesons within acceptance ofε┴ = 30π mm and εL = 150π mmafter cooling

180 MeV

Harold G. Kirk

Compare 50m to Post-Cooling

!

Harold G. Kirk

Step 1: Vary the Target Radius

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.022000

24000

26000

28000

30000

32000

10GeV Beam at 67mrad beam angle and 33mrad beam/jet crossing angle

Mes

ons

Target Radius, cm

Positives+Negatives Polynomial Fit(3rd order)

Rmax=0.48cm

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 1.7×1013 protons per bunch at 10 GeV

Bunch length 1–3 ns

Train length at least 200 μs

Harold G. Kirk

Optimizing Soft-pion Production

Harold G. Kirk

Step 2: Vary the Beam Angle

20 40 60 80 100 120 140 160 180 200 22016000

18000

20000

22000

24000

26000

28000

30000

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10GeV Beam-Mesons at 0.48cm target radiusand 33mrad beam/jet crossing angle

Positives+Negatives Polynomial Fit (3rd Order)

Mes

ons

Beam Angle, mrad

beam=89mrad

Harold G. Kirk

Step 3: Vary the Beam/Jet Crossing Angle

10 20 30 40 50 60

28000

29000

30000

31000

32000

33000

10GeV Beam at 0.48cm target radius and 89mrad bem angle

Mes

ons

Angle between Beam and Jet, mrad

Positives+Negatives Polynomial Fit(3rd order)

crossing=25mrad

Harold G. Kirk

Post-cooling 30π Acceptance