4thth 03) beam dump design for j parc neutrino project2003/12/3 nbi03, kek, november 7~11th, 2003 1...

2003/12/3 NBI03, KEK, November 7~11th, 2003 1

44thth International Workshop on Neutrino Beams and Instrumentation International Workshop on Neutrino Beams and Instrumentation (NBI(NBI’’03)03)

Beam Dump Design forBeam Dump Design forJJ--PARC Neutrino ProjectPARC Neutrino Project

In collaboration with In collaboration with A.K.Ichikawa, T.IshidaA.K.Ichikawa, T.Ishida**, J.Kameda , J.Kameda

T.Kobayashi, M.T.Kobayashi, M.SakudaSakuda, Y., Y.OyamaOyama, & Y.Yamada (KEK IPNS), & Y.Yamada (KEK IPNS)JJ--PARCPARCνν construction groupconstruction group

1. RequirementsRequirements2.2. MARS Simulation for Beam Dump MARS Simulation for Beam Dump 3.3. Beam Dump CoolingBeam Dump Cooling4.4. Layout of Beam Dump & Layout of Beam Dump & MuonMuon PitPit5.5. Summary & ScheduleSummary & Schedule


1. 1. Requirements for BD/MUPITRequirements for BD/MUPIT•• Radiation shielding at operationRadiation shielding at operation

<< 11mSv/h11mSv/h at the edge of shield (Outer Concrete at the edge of shield (Outer Concrete –– Soil)Soil)

•• Residual dose rate in the Residual dose rate in the muonmuon pitpit< 12.5< 12.5μμSv/hSv/h for the normal controlled area. for the normal controlled area.

•• Beam dump cooling Beam dump cooling ~~¼¼ of total heatof total heat is deposited in the Beam Dump. is deposited in the Beam Dump.

•• Radiation in cooling waterRadiation in cooling waterH.E.H.E.γγ((1616N,N,1414O), delayed neutron emission(O), delayed neutron emission(1717N): cooling N): cooling system should also be shielded and be in underground. system should also be shielded and be in underground. 33H production: We are planning to dispose it (H production: We are planning to dispose it (<15Bq/cc<15Bq/cc) ) by dilution. by dilution. Hadron fluenceHadron fluence at cooling place should be at cooling place should be enough low = Cooling path should be as far as possible enough low = Cooling path should be as far as possible from beam center.from beam center.

•• RedundancyRedundancyCore part is highly radioCore part is highly radio--active so it is hard to access. active so it is hard to access. Need to bear 20 years, also for 4MW operation.Need to bear 20 years, also for 4MW operation.


Decay Volume, Beam Dump and MUPITDecay Volume, Beam Dump and MUPIT

110m

An updated designAn updated designwill be shown laterwill be shown later


2. 2. MARS Simulation for Beam DumpMARS Simulation for Beam Dump

•• ΦΦ-- symmetrical geometry with iron + concretesymmetrical geometry with iron + concreteΔΔrr=10/5cm,=10/5cm, ΔΔzz=20/5cm, corresponding to OAB 2=20/5cm, corresponding to OAB 2°°

•• Calculate incoming particle flux, energy deposit,Calculate incoming particle flux, energy deposit,hadron fluencehadron fluence, and dose equivalent of each volume , and dose equivalent of each volume and obtain critical boarder lines for BD design: and obtain critical boarder lines for BD design:

Energy Deposit= 0.02Joule/cmEnergy Deposit= 0.02Joule/cm33=5,000W/m=5,000W/m33

= DV plate coil, boarder between Iron and Concrete. = DV plate coil, boarder between Iron and Concrete.

Hadron FluenceHadron Fluence = 1= 1××1010--5 5 (2(2××1010--66) /cm) /cm22/proton/proton

at cooling path for 750kW (4MW) operationat cooling path for 750kW (4MW) operation

Dose Equivalent =11Dose Equivalent =11mSvmSv / hour / (factor), where/ hour / (factor), where

　　 factor = factor = ““Threshold factorThreshold factor”” (2)(2)××[Safety(2)][Safety(2)]

Former comes if we set neutron energy cutoff threshold Former comes if we set neutron energy cutoff threshold (10(10--33eVeV→→20MeV) in the simulation to save CPU time. 20MeV) in the simulation to save CPU time.

For 4MW operation, latter is taken into account already in For 4MW operation, latter is taken into account already in the design valuethe design value


ΦΦ-- symmetrical Geometrysymmetrical Geometry

•• Beam: Beam: ΔΔxx,y=0.424cm / ,y=0.424cm / ΔΘΔΘxx,y=0.5mrad,y=0.5mrad•• HORN Magnetic Field ON/OFFHORN Magnetic Field ON/OFF•• MUON ProductionMUON Production ON/OFFON/OFF


Results:Results: Incoming Particle Flux(1)Incoming Particle Flux(1)

OFFOFF

/ 100,000 / 100,000 p.o.t.p.o.t.

HORN ONHORN ON


Results:Results: Incoming Particle Flux(2)Incoming Particle Flux(2)

/ 100,000 / 100,000 p.o.t.p.o.t.

Protons w/o interaction at target (~17%, Protons w/o interaction at target (~17%, σσxx,y= 15cm),y= 15cm)


Results:Results: Energy Deposit and Energy Deposit and Hadron FluenceHadron Fluence

0.020.02J/cmJ/cm33

(Fe-Concrete)

22ee--6 6 /cm/cm22/P/P(Cooling Water Path)

16 16 J/cmJ/cm33, +4.6, +4.6℃℃/spill/spill

MUONMUON

DV He

BD Fe

Concrete

Fe ~1.5mFe ~1.5m

~2.5~2.5mm

~2.5~2.5mm

~1.7~1.7mm


Results:Results: Energy Deposit with/without Energy Deposit with/without Muon Muon ProductionProduction

DV He

BD Fe

Concrete

Possible MUPIT location: Fe 3.5m equivalentPossible MUPIT location: Fe 3.5m equivalent


Results:Results: Dose EquivalentDose Equivalent

DV He

BD Fe

Concrete

Iron 4m + Iron 4m + Concrete 1.5mConcrete 1.5m

Fe ~1.5mFe ~1.5m100 100 SvSv/h/h(Fe-Concrete)

1111mSv/hmSv/h(Concrete-Soil)


3. 3. Beam Dump CoolingBeam Dump Cooling•• Compared to K2K, JPARCCompared to K2K, JPARCνν project employs project employs ××150 150

intense beam. An efficient cooling is necessary.intense beam. An efficient cooling is necessary.

•• Choice of core materialChoice of core materialInput: MARS simulation energy deposit, scaled by Input: MARS simulation energy deposit, scaled by material density.material density.Check temperature distribution both by static calculation Check temperature distribution both by static calculation and by transient heat simulation by NASTRAN code. and by transient heat simulation by NASTRAN code.

308

4,0004,0005050SJHFSJHF--HKHK

PowerPower(kW)(kW)

EEpp((GeVGeV))SuperSuper--beam beam

facilitiesfacilities

7507505050JHFJHF--SKSK

410120NuMINuMI

300400CNGSCNGS

512((K2K)K2K)

1,0001,000

190190

60

30

5

~1

BD loss BD loss (kW)(kW)

Al+Fe core Al+Fe core modulesmodules

Graphite+Graphite+Al ModuleAl Module

Air CoolingAir Cooling

(none)

Cooling Cooling SchemeScheme


Temperature distribution at EquilibriumTemperature distribution at Equilibrium

Ex. Core material: Ex. Core material: Cu(Cu(λλ=400W/m=400W/m・・K)K)

100 600

300

1.5m

Q( r)

T(r )-TR

α(Δt=50℃)

5002000

1.5m

750750kWkW 44MWMW

TT(r=0)(r=0)--TT(1.5m)(1.5m)=125=125℃　℃　αα(1.5m)(1.5m)=600W/m=600W/m22KK

TT(r=0)(r=0)--TT(60cm)(60cm)=300=300℃　℃　αα(60cm)(60cm)=4kW/m=4kW/m22KK

TT(r=0)(r=0)~125+50+30=200~125+50+30=200℃℃


Comparison of Comparison of Core Material CandidatesCore Material Candidates

3.83.8

1.2

0.8

3.2

Max.Max.DepDep(J/cm(J/cm33))750kW750kW

1.51.5

5.0

6.5

2.0

Core Core LengthLength

(m)(m)

400400

240

~150

75

ConducConductivitytivity

(W/(W/mKmK))

1,0851,085

660

>3,500

1,535

MeltingMeltingTemp.Temp.

((℃℃))

+155+155℃℃(820)(820)

+80℃(420)

+85℃(440)

+660℃(3,800)

Max Max TempTemp

750kW750kW(4MW)(4MW)

ααW/mW/m22KK

750kW750kW(4MW)(4MW)

DensityDensity(g/cm(g/cm33))

700700(3.5(3.5k)k)

8.98.9CopperCopper

200(1.1k)

2.7AluminiumAluminium

140(700)

1.8GraphiteGraphite

600(3k)

7.8IronIron

In case of In case of Cooling at r=1.5mCooling at r=1.5m

•• Higher density = higher local energy deposit Higher density = higher local energy deposit = smaller core size= smaller core size☺☺ = smaller amount of water= smaller amount of water☺☺

•• Cu has the highest heat conductivity.Cu has the highest heat conductivity.= further cooling water path = further cooling water path = lower= lower hadron fluencehadron fluence at cooling surfaceat cooling surface☺☺


Transient heat analysis (NASTRAN)Transient heat analysis (NASTRAN)

4,4904,490IronIron4MW4MW

748748℃℃CopperCopper4MW4MW

849849IronIron750kW750kW

147147℃℃CopperCopper750kW750kW

Max.Max.

Consistent to the Consistent to the analytic calc.analytic calc.750kW is OK with750kW is OK withCopper core.Copper core.Need measure Need measure for 4MW.for 4MW.

Cooled with Cooled with ConvConv. . CoefCoef..

=600W/m=600W/m２２・・KK


Cooling Water and Its TreatmentCooling Water and Its Treatment(rough estimation)(rough estimation)

What we need:What we need:22××1.51.5×π××π×1.5=14.1m1.5=14.1m22, , ×× αα=700W/m=700W/m22KK

Cool core by 1Cool core by 1inchinchφ×φ×20 20 pathespathes750kW750kW××1/41/4××1/20 = 9.4kW/path1/20 = 9.4kW/pathTotal amount of water in tubes = Total amount of water in tubes = 13 litter13 litterWater flow rate = Water flow rate = 30litter/min30litter/min = 1.16m/s= 1.16m/s⇒⇒ ΔΔTTwaterwater=4.5=4.5℃℃, , αα=4.9kW/m=4.9kW/m22KK

Inner surface area in total = 2.2mInner surface area in total = 2.2m2 2

　　⇒　　　⇒　2.22.2××4.9 ~ 14.14.9 ~ 14.1××0.7 0.7

Water system:Water system:A circulation path with heat exchanger A circulation path with heat exchanger + a dilution path.+ a dilution path.The dilution path= a deposit tank + a dilution tank The dilution path= a deposit tank + a dilution tank to dispose water with < 15Bq/cc.to dispose water with < 15Bq/cc.BD: 2.6mBD: 2.6m33 when diluted to 15Bq/cc equivalent.when diluted to 15Bq/cc equivalent.

Details was presented in Details was presented in ““Radiation Safety IssuesRadiation Safety Issues””

1.5

1.5

mm

1.51.5mm


4. 4. Layout of Beam Dump and Layout of Beam Dump and MuonMuon PitPitCooling Cooling

pathpath

Dose EquivalentDose Equivalent~100(40)~100(40) mSvmSv/h/h

Residual Residual DoseDose (30d/1d)(30d/1d)0.2(0.05)0.2(0.05) uSvuSv/h/h

MuMuPitPit

Cooling pit Cooling pit (Heat Exchange)(Heat Exchange)

Iron block Iron block 660t660t

(DURATEC?)(DURATEC?) Temp. raiseTemp. raiseAir: +1Air: +1℃℃/1.2h/1.2hConcConc:+1:+1℃℃/1.8h/1.8h(Air conditioned)(Air conditioned)

CoreCoreCu 230tCu 230t


Hadron FluenceHadron Fluence

DOSEDOSE　　EqEq..

22ee--6 6 /cm/cm22/P/P(Cooling Water Path)

1111mSv/hmSv/h(Concrete-Soil)

100 100 SvSv/h/h(Fe-Concrete)


5.5. SummarySummary•• A possible BD/MUPIT design is shown.A possible BD/MUPIT design is shown.

Materials to MUPIT: Materials to MUPIT: EEμμ>4.5GeV>4.5GeVCopper core(1.5m)+Iron block(1.5m)+Concrete(0.5m)Copper core(1.5m)+Iron block(1.5m)+Concrete(0.5m)Hadron Fluence Hadron Fluence / residual dose at MUPIT is low enough./ residual dose at MUPIT is low enough.Hadron fluence Hadron fluence at cooling path around core is equal to or at cooling path around core is equal to or less than that of DV plate coil, to dispose it with < less than that of DV plate coil, to dispose it with < ××200 200 dilution.dilution.Convection Convection coefcoef.=700W/m.=700W/m22・・K for 750kW operation is K for 750kW operation is enough realistic. enough realistic.

•• Detailed BD core design is under progress.Detailed BD core design is under progress.Need measure for 4MW operation. This can be achieved Need measure for 4MW operation. This can be achieved with a cooling path at around r=60cm.with a cooling path at around r=60cm.

Requirements for Requirements for muonmuon profile monitor settled after BD (J.Kameda)profile monitor settled after BD (J.Kameda)Good sensitivity for magnet and proton beam position with Good sensitivity for magnet and proton beam position with 2~5 2~5 GeVGeV/c/cthreshold and no big difference in this region.threshold and no big difference in this region.Above ~ 7Above ~ 7 GeVGeV/c, the sensitivity become worse./c, the sensitivity become worse.With 5GeV/c threshold, With 5GeV/c threshold, muon fluencemuon fluence is ~10is ~1088/spill/cm/spill/cm22. . Possible design is under discussion with physics group.Possible design is under discussion with physics group.


ScheduleSchedule2004 2005 2006 2007 2008FY2003

Conceptual designConceptual designTechnical designTechnical design

Civil constructionCivil construction

Iron blockIron block

07/3107/31

CoreCoreProductionProduction InstallationInstallation

ImportImport InstallationInstallation

Installation

K2KK2K

InstallationWater systemWater system

4thth 03) beam dump design for j parc neutrino project2003/12/3 nbi03, kek, november 7~11th, 2003 1...

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