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Optical Diagnostic Results of MERIT Experiment and Post-Simulation

H. Park, H. Kirk, K. McDonald

Brookhaven National LaboratoryPrinceton University

Stonybrook University

January 26, 2009

Neutrino Factory And Muon Collider Collaboration Meeting Lawrence Berkeley National Laboratory, CA

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Talk Outline & Introduction

● Introduction : Aim of work - Understand the optical diagnostic results from experiment. - Do post-simulation with the experimentally observed results. - Investigate the characteristics of mercury jet flow through the comparison of theoretical calculated results with experimental results.

● Experimental Results - Optical diagnostic observation of jet flow using short laser pulsed retro-back shadow-photography. - Behavior of mercury jet in magnetic fields: stabilization, destabilization, flow velocity, drop/filaments velocity. - Proton beam structures. (CERN, G. Skoro) - Disruption of mercury jet by interaction of mercury jet with an intense proton beam in magnetic fields.

● Post-Simulation Results - Calculation of energy deposition density by an intense proton beam. (FNAL, S. Striganov) - Calculation of mercury drop velocity by the deposited energy presssurization.

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Mercury Intense Target Experiment : October 22, 2007 ~ November 11, 2007

Setup of key components for MERIT experiment

Beam axis

Magnet axis

Mercury Jet

Nozzle Viewport 130cm

Viewport 245cm

Viewport 360cm

Viewport 490cm

67 milliradian

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Influence of Magnetic Field and Gravity to Jet Trajectory

Magnet Axis &Direction

Beam axis& Direction67 milliradian

At nozzle, 33 milliradian

At 45 cm,10 milliradian

At 45 cm, 57 milliradian

At 45 cm, beam is steered to hit the center of Hg jet

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Longitudinal Hg Jet Stream Velocity along Distance from Nozzle

Boundary layer induced by a jet emerging from a nozzle

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Stabilization of Jet Surface by Magnetic Field

0.4T 5T

15T10T

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Hg Jet Height vs. Magnetic Field and Distance from Nozzle

Jet distortion vp1 vp2 vp3 (R. Samulyak, BNL, 2008)

(R. Samulyak, BNL, 2008)

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Beam Pulse Structure and Beam Size from Beam Optics and Camera Screen

(G. Skoro, U. Sheffield, 2008)

(I. Efthymiopoulos, CERN, 2008)(G. Skoro, U. Sheffield, 2008)

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Beam Shape from Screen Shots

Intensity <= ‘saturation intensity’

Intensity = 100x ‘saturation intensity’

Simulations Experiment

~ 0.2 Tp ~ 0.3 Tp

~ 30 Tp ~ 30 Tp

(G. Skoro, U. Sheffield, 2008)

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(S. Striganov, FNAL, 2009)

Beam Jet Interaction Model in MARS Code

Input Parameters

Beam spot size(cm) by beam intensity 1Tp, 3Tp, 10Tp, 30Tp

Jet size(cm) -

Magnetic field strength(T) 0, 5, 10

Jet trajectory(cm) -

Beam momentum(GeV/c) 24

Hg density(g/cm^3) 13.546

Output Results

Energy deposition density (GeV/g/proton)

Volumes(cm^3)

(Beam spot size: CERN calculated, G. Skoro measured)

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0 20 40 60 80

0

5

10

15

20

25

30

35

40

45 Vertical = -0.7155 cm Vertical = -0.5565 cm Vertical = -0.3975 cm Vertical = -0.2385 cm Vertical = -0.0795 cm Vertical = 0.0795 cm Vertical = 0.2385 cm Vertical = 0.3975 cm Vertical = 0.5565 cm Vertical = 0.7155 cm

Ave

rage

d e

ner

gy d

epos

itio

n (

J/g)

Distance from nozzle (cm)

Energy Deposition vs. Vertical Length in Jet Section and Distance from Nozzle, B=10T, N=10Tp

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Images of Jet Flow at Viewport 3, B=10T, N=10Tp, L=17cm, 2ms/frame

t = 20 ms t = 18 ms t = 16 ms t = 14 ms

t = 12 ms t = 10 ms t = 8 ms t = 6 ms

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0 20 40 60 80

0

5

10

15 Vertical = -0.7155 cm Vertical = -0.5565 cm Vertical = -0.3975 cm Vertical = -0.2385 cm Vertical = -0.0795 cm Vertical = 0.0795 cm Vertical = 0.2385 cm Vertical = 0.3975 cm Vertical = 0.5565 cm Vertical = 0.7155 cm

Ave

rage

d e

ner

gy d

epos

itio

n (

J/g)

Distance from nozzle (cm)

Energy Deposition vs. Vertical Length in Jet Section and Distance from Nozzle, B=5T, N=3Tp

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Images of Jet Flow at Viewport 3, B=5T, N=3Tp, L=11cm, 2ms/frame

t = 18 ms t = 16 ms t = 14 ms

t = 12 ms t = 10 ms t = 8 ms

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Images of Jet Flow at Viewport 2, B=7T, N=8Tp, L=11cm, 500µs/frame

t = 0 µs

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0 20 40 60 80

0

1

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3

4

5

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7 B = 0 T B = 5 T B = 10 T

Ave

rage

d e

ner

gy d

epos

itio

n (

J/g)

Distance from nozzle (cm)

Energy Deposition vs. Magnetic Field and Distance from Nozzle, N=3Tp

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0 20 40 60 80

0

2

4

6

8

10

12 = 29o

= 68o

= 84o

= 96o

= 112o

= 151o

= 209o

= 248o

= 264o

= 276o

= 292o

= 331o

Ave

rage

d e

ner

gy d

epos

itio

n (

J/g)

Distance from nozzle (cm)

Top =90ºBottom = 270º

Energy Deposition vs. Angle in Jet Section and Distance from Nozzle, B=5T, N=3Tp

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0 45 90 135 180 225 270 315 3600

2

4

6

B = 0 T B = 5 T B = 10 T

Ave

rage

d e

ner

gy d

epos

itio

n (

J/g)

Angle in jet sectional area ( degree )

Energy Deposition vs. Magnetic Field and Angle in Jet Section, N=3Tp

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0 20 40 60 80

0

5

10

15

20 N = 3 Tp N = 10Tp N = 30 Tp

Ave

rage

d e

ner

gy d

epos

itio

n (

10-1

3 J/g

/pro

ton

)

Distance from nozzle (cm)

Energy Deposition vs. Number of Protons and Distance from Nozzle, B=10T

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2 4 6 8 10 12 140.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0

1

2

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B = 0 T, Fit B = 10 T, Fit B = 0 T, Beam spot by optics B = 5 T, Beam spot by optics B = 10 T, Beam spot by optics B = 0 T, Beam spot by screen B = 10 T, Beam spot by screen

B = 0 T, Total E, Beam spot by optics B = 5 T, Totel E, Beam spot by optics B = 10 T, Total E, Beam spot by optics

Tot

al e

ner

gy d

epos

itio

n (

GeV

/pro

ton

) P

eak

en

ergy

dep

osit

ion

(G

eV/g

/pro

ton

)

Beam sectional area (mm2)

xopticsbeam

xThresholdNopticsbeamThresholdNpeak

peak

A

AEE 1

,

1

,,,

Peak Energy Deposition Density vs. Beam Sectional Area and Magnetic Fields

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0 5 10 15 20 25 30 35 400

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50

75

100

125

150

175

200 B = 0 T, Fit B = 10 T, Fit B = 0 T, Beam spot by optics B = 10 T, Beam spot by optics B = 0 T, Fit, Beam spot by camera B = 10 T, Fit, Beam spot by camera B = 0 T, Beam spot by camera B = 10 T, Beam spot by camera

Pea

k e

ner

gy d

epos

itio

n (

J/g)

Number of protons (Tp)

Threshold of disruption

Peak Energy Deposition vs. Number of Protons and Magnetic Fields

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0 5 10 15 20 25 300.0

0.1

0.2

0.3

0.4 B = 0 TB = 5 TB = 10 TB = 15 T

D

isru

pti

on le

ngt

h (

m)

Number of protons (Tp)

B = 0 T, Estimation, Beam size by opticsB = 10 T, Estimation, Beam size by opticsB = 0 T, Estimation, Beam size by camera

24 GeV/c

Disruption Length vs. Estimation

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Investigation of Hg Jet Interacting with 24GeV 10Tp Beam in 10T Field, 25µ/frame

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Velocity of Mercury Filament in Magnetic Fields

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Time Response of Mercury Filament, B=10T, N=10Tp

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Geometry of Viewing of Drops and Probabilistic Drop Velocity

b

a

y_m

D Focal point

Drop

θ

øs

1. Uniform in θ

2. Uniform in ø

3. Uniform in position s around the circumference C

ddp2

1)(

ddp2

1)(

dsC

dP1

)( (K. McDonald, Princeton U., 2008)

Jet shape P(θ)Velocity (m/s)

Mean Sigma

Ellipse

Uniform in theta 38 13

Uniform in phi 47 18

Uniform in s 43 16

Circle

Uniform in theta 37 12

Uniform in phi 38 13

Uniform in s 38 13

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T.Davenne, 2008

Velocity response of 2cm diameter mercury jet.No magnetic Fields are employed.

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2

1)(

2VT

KE

Numerical Simulation of Sievers & Pugnat Result

(T. Davenne, RAL, 2008)

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0 5 10 15 20 25 30

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120

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160 B=0T B=5T B=10T B=15T Optics, B=0T Optics, B=5T Optics, B=10T Camera, B=0T Camera, B=10T

F

ilam

ent

velo

city

(m

/s)

Number of protons (Tp)

24 GeV/c

Filament Velocity vs. Number of Protons and Magnetic Fields and Comparison with Estimated Numerical Simulation Results

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Conclusions and Future Work

1. Mercury jet behaviors in magnetic fields were investigated experimentally and approximately compared with simulation/literatures.

2. Elliptic jet shape was approximated, but circular model with reduced density will be investigated and compared for review of validation. 3. Proton beam structures were investigated experimentally. (CERN, G.Skoro) 4. Energy deposition was calculated based on the experimental results and the distribution of energy deposition was investigated and well compared with optical diagnostic captured images. The energy deposition is varying with beam sectional area and magnetic fields and is dependent on the jet shape. (FNAL, S. Striganov)

5. The results from simulation was used for evaluation of experimental results. The comparison of disruption length implicitly shows the validation of beam spot size estimation and the comparison of filament velocity shows somewhat consistent relationship with energy deposition calculation, numerical velocity calculation, and experimental measurements.