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Energy Deposition of 4MW Beam Power in a Mercury Jet Target

X. Ding, D. B. Cline UCLA

H. Kirk, J. S. Berg BNL

The International Design Study for the Neutrino Factory

FNAL

April 8-10, 2010

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Outline

1. Introduction

2. Target Geometry

3. Energy Deposition from MARS15

4. Comparison with FLUKA

5. Power Distribution, radiation dose and life time for SC1 coil

6. Summary

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Introduction

• Using MARS15 to study energy deposition.

• Study II geometry and magnetic field map.

• Hg jet:

r=0.5cm, tilt 100mrad to sol. axis.

• Proton beam:

Simple Gaussian distribution, r=0.15cm, tilt 67mrad to sol. axis.

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Introduction (Cont’d)

• The unit of energy deposition is GeV or GeV/g p.p (GeV per gram per incident proton).

• The number of particles for (4MW, 10GeV) proton beam is 2.5*1015 s-1 (an average beam intensity in particles per second).

(2.5*1015)*(10*109)*(1.6*10-19)*10-6 =4MW

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Target Geometry

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Target Geometry (Cont’d)

Res Sol

Hg Jet

SC1 SC2 SC3 SC4 SC5

FeCo

Pre-Trgt

Air

BeWindow (z=600cm)

Hg Pool

WC Shield

STST Env(Bottle)

Hg Jet

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Energy Deposition of 4MW Beam Power

Regional Name ED [GeV] P [kW]

P/Pbeam [%]

WC shield 4.6 1837.6 46.0

Hg Jet 1.065 426.0 10.7

STST Env 1.17 468 11.7

Res Sol 2.62*10-1 104.6 2.6

Hg Pool 4.89*10-2 19.5 0.5

FeCo 2.25*10-2 9.0 0.225

Be Window 6.22*10-3 2.5 0.06

Pre Trgt < 10-3 ----- -----

Air < 10-3 ----- -----

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Energy Deposition of 4MW Beam Power (Cont’d)

Regional Name

ED [GeV] P [kW] P/Pbeam [%]

SC1 5.52*10-2 22.1 0.55

SC2 5.99*10-3 2.4 0.06

SC3 3.30*10-3 1.3 0.03

SC4 1.19*10-3 0.5 0.01

SC5 2.87*10-4 0.12 0.003

SC6 1.98*10-4 0.08 0.002

SC7 8.70*10-3 3.5 0.09

SC8 3.71*10-3 1.5 0.04

SC9 2.18*10-3 0.9 0.02

SC10 1.81*10-3 0.7 0.02

SC11 1.33*10-3 0.5 0.01

SC12 8.69*10-4 0.35 0.01

SC13 6.51*10-3 2.6 0.07

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Distribution of Energy Deposition

The energy deposition in SC1 coil is between 10-8 and 10-10 [GeV/g per incident proton].

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Comparison with Fluka

Power Deposition in NuFact Target, J. Back (Warwick, Dec 8, 2009). (http://www.hep.princeton.edu/~mcdonald/mumu/target/index.html#2nd_OP_workshop)

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Comparison with Fluka (Cont’d)Region P [kW] % (MARS15) P [kW] %

(FLUKA)

Hg Jet

Hg Pool inside WC shield

WC shield (z < 27 cm)

WC shield (z ≥ 27 cm)

Outer Fe yoke (z < −165 cm)

Inner Fe yoke (z ≥ −165 cm)

Inner Cu coil (18 ≤ r ≤ 23 cm)

Outer Cu coil (23 < r ≤ 49 cm)

SC Coil 1

SC Coil 2

SC Coil 3

SC Coil 4

SC Coil 5

SC Coil 6

SC Coil 7

SC Coil 8

SC Coil 9

SC Coil 10

SC Coil 11

SC Coil 12

SC Coil 13

Be window at 6m

426.0 10.7

19.5 0.5

1837.6 (WC shield) 46.0

468 (STST Env) 11.7

9.0 0.2

(FeCo)

104.6 2.6

(Res Sol)

22.1 0.6

2.4 0.1

1.3 -----

0.5 -----

0.1 -----

<0.1 -----

3.5 -----

1.5 -----

0.9 -----

0.7 -----

0.5 -----

0.4 -----

2.6 -----

2.5 -----

400.9 10.0

12.5 0.3

1845.5 46.1

848.3 21.1

----- -----

15.2 0.4

142.0 3.6

90.3 2.3

52.7 1.3

5.5 0.1

1.2 -----

0.4 -----

0.1 -----

<0.1 -----

1.1 -----

0.5 -----

0.2 -----

0.1 -----

0.1 -----

0.1 -----

0.7 -----

1.7 -----

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Power Deposition and Radiation Dose in SC1 Coil

• The max. energy deposition at the SC1 coil is 10-8 GeV/g per incident proton. So the max. power deposition per kg at SC1 coil is 4W/kg. 10-8*(109)*(1.6*10-19)* 2.5*1015 * 103 =4 W/kg• The average power per kg is 0.46 W/kg. (22.1 kW, 4.8*104 kg)•1yr=2*107 s and 1Gy=1J/kg.• The max. and average radiation dose per year in SC1 coil is 8*107 (Grays/2*107 s) and 9.2*106 (Grays/2*107 s), respectively.

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Lifetime of SC1 CoilSC coil in Study II (Table 3.4) : (http://www.cap.bnl.gov/mumu/studyii/final_draft/chapter-3/chapter-3.pdf)

Component

Dose/yr(Grays/2*107 s)

Max allowed Dose(Grays)

1 MW Life(years)

4 MW Life(years)

SC coil 6*106 108 16 4Max allowed Dose (see Al Zeller, Radiation Issues in Capture Solenoid)(http://www.fnal.gov/projects/muon_collider/nu-factory/subsys/ss-target/scan3.pdf)

Evaluation of life time for SC1 coil: Component

Dose/yr(Grays/2*107 s)

Max allowed Dose(Grays)

1 MW Life(years)

4 MW Life(years)

SC1 coil (max)

8*107 108 1.25 0.3

SC1 coil(ave)

9.2*106 108 10.8 2.7

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Enhanced Shield for SC Coils(WC shield is extended from R=50 to R=63 cm.)

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Energy Deposition in SC coils (4MW beam, enhanced shield)

Regional Name

ED [GeV] P [kW] P/Pbeam [%]

SC1 1.199*10-2 4.8 0.12

SC2 9.04*10-4 0.36 0.01

SC3 6.7*10-4 0.27 0.01

SC4 2.18*10-4 0.09 0.002

SC5 1.34*10-4 0.05 0.001

SC6 1.51*10-4 0.06 0.002

SC7 8.49*10-3 3.40 0.08

SC8 3.61*10-3 1.44 0.04

SC9 2.13*10-3 0.85 0.02

SC10 1.23*10-3 0.49 0.01

SC11 8.28*10-4 0.33 0.01

SC12 9.5*10-4 0.38 0.01

SC13 6.39*10-3 2.54 0.06

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Enhanced Shield for SC Coils(No Res Sol, WC shield is extended from R=50 to R=63 cm.)

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Energy Deposition in SC coils (4MW beam, no Res Sol, enhanced shield)

Regional Name

ED [GeV] P [kW] P/Pbeam [%]

SC1 3.21*10-3 1.30 0.03

SC2 5.88*10-4 0.24 0.006

SC3 6.53*10-4 0.26 0.007

SC4 1.97*10-4 0.08 0.002

SC5 1.09*10-4 0.04 0.002

SC6 1.56*10-4 0.06 0.002

SC7 7.95*10-3 3.18 0.08

SC8 4.14*10-3 1.66 0.04

SC9 2.62*10-3 1.05 0.03

SC10 1.45*10-3 0.58 0.01

SC11 8.53*10-4 0.34 0.01

SC12 9.77*10-4 0.39 0.01

SC13 6.74*10-3 2.70 0.06

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Distribution of Energy Deposition (No Res Sol, WC shield is extended from R=50 to R=63 cm.)

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Summary

• The bulk of the 4MW beam power is deposited in the tungsten-carbide shield, Hg Jet and STST Env.

• Both MARS 15 and FLUKA simulations give us similar results.

• Power deposition and radiation dose for SC1 coil are calculated and the life time of SC1 coil is evaluated based on the Study II document.

• Enhanced shield can decrease the power deposition in SC1 coil from 22.1kW to 4.8kW. By replacing the Res Sol by WC shield, the power deposition in SC1 coil can be decreased further to 1.3kW.