Neutrino target station
at JPARC
Yoshikazu Yamada (KEK)
Y.Hayato, E.Hirose, A.K.Ichikawa, T.Iwashita,
T.Kobayashi, S.Koike, T.Miura, H.Nakano,Y.Oyama, N.Sato, T.Suzuki, Y.Yamanoi
4th International Workshop on
the Neutrino Beams and Instrumentation
November 11, 2003
Contents•Introduction•Radiation (detail: talked by Oyama)•Support system & maintenance•Cooling system•Schedule

Neutrino beam line and target
Target1400

1st Horn

2000

2nd Horn

Fast-extracted
proton beam line Target

Station50GeV PS

900472

0.75MW
beam809
1400•Carbon target: 30mm-φ,900mm-L•beam size: σr ~6mm

100 cm2500

3rd Horn

Decay Beamvolume dumpν beam to SKNeutrino target station
22m

33m

11m

40 ton craneGround level

22m
Service pit

Machineroom

Iron shield

Beamwindow
Decay
volumeHelium
container
Iron shield

Finalfocus

Concrete blocks

Storage forradioactive material

Beam window
Concrete shield
BaffleTarget & 1st horn 2nd horn 3rd horn

Shielding and radiation level< 12.5µSv/h@floor of surface building

Concrete: 4.5m

Concrete:1m

Iron:1.5m

Concrete:3.6m

0.75MW
operation

Iron:2.2mIron:1.5m

Concrete:4.4m

fence< 0.25µSv/h@out of the control area

concrete wall : 20cm-t< 5mSv/h@boundary of concreteconfirmed by MARS
detail ⇒ Oyama’s talkResidual dose
One (seven) day coolingafter one year operation(by MARS)
Floor of service pit~0.1(0.07) µSv/h

Machineroom

Upper iron shield
Outer : 22(16) µSv/h
Inner : 0.56(0.42) Sv/h
Aluminum wall
~0.65(0.17) Sv/hdetail ⇒ Oyama’s talk

Service pit

Side view of target area
15mService pit
Bus barBus bar

Helium container
Bus barConcreteshield

1mIronshield

2.2m
Collimatorfor DV

Support of horn
WindowBaffle

Target+
1st horn 2nd horn

Aluminum wall

Iron shield
Concrete shield

3rd hornFront view of target area
Undergroundmachine room

Concrete shield block
Service pit Helium container
Bus bar

Transformer

Area for additionalshields for 4MW

IronshieldSupport of horn
1st horn

6m Iron shieldstorage for radioactive
material

Concreteshield block

Aluminum wall
3m

Concrete shieldHelium container
Helium container
Bus barConcrete shield block

Ironshield

1st horn
Iron shield•3m(W)×6m(H)×15m(L), 5cm-thick iron wall•Filled by Helium gas (1-atm, 130m3, ~99%)•Reduce Tritium production : ~1/25?
• σ~30mb for Air, σ~1.2mb for He•Tritium production after 200 days operation:
Air:800Bq/cm3, He:30Bq/cm3•Ventilation time after 200 days operation
Air:110days, He:5days(ventilation: 8000m3/hour, regulation:5mBq/cm3)•Reduce corrosion by NOx : ~1/100?
•20cm thick Aluminum wall in target area
reduce surface dose by ~1/10 at maintenanceSupport system of horn
Concrete shield

supporthearIronshieldSupportof horn

supportalignment

Exchange of the target/ horn•Upper Iron and concrete shields are removed.
•Highly radioactivated target/horn are moved underground-level and kept in the storage of radioactive
materials for several years.
•New target/horn are installed and shields are installed.
•All works should be done remotely.
top view

storage of radioactive
materials

Cross-sectionalview

Ground level

Exchange of the target
A) If horn is broken, scrap target and horn.
B) If target is broken;
1) Scrap target and horn.
or2) Replace broken target with new one in the horni) at the storage for radioactive material.
orii) at the beam line.

All works should
be done remotely.

Heat load on Al-wall/Fe-shield
Heat load : ~170 kW on Aluminum, 40kW on Iron
Concrete shield㪈.00E+05

MARSAluminum㪈.00E+04
Fe(1st 20cm)

Energy(W/m)
Energydeposit(W/m)

Iron shield㪈.00E+03Fe㪈
Fe2Fe(2nd 20cm)

㪈.00E+02

Fe4
Fe6Fe7Fe8

㪈.00E+00
㪈.00E-0㪈
700

Fe3Fe5

㪈.00E+0㪈

Iron shield

Aluminum

㪈200

㪈700
Z(cm)

2200

Cooling for Aluminum wall
Water pipe for Aluminum wall
Concrete shield(option for 4MW)

Temperature rise in Al wallQAl=17/8(kW/m), L= 3/2(m),Iron shield

αAｌ=240(W/mK), A=0.2(m2)

Q Al × L / 2= 33( K )∆T =α Al × A

Water flow =170(kJ/s)/4.2(J/g/K)/10(K)/8=30(Litter/min.)(×8)
1-inch tube: Re=32000, k=4860(W/m2K),
Iron shield⇒ ∆T=3.7(K)、∆P=0.11(kg/cm2)
Radio activity of water ⇒ Oyama’s talk

Cooling for Iron shield
Water pipe for upper iron shield
Concrete shield

Air cooling surface for iron shield
Outer surface (Default)
Middle surface (Option for 4MW)
Inner surface (Option for 4MW)

Iron shield

Temperature rise in iron shield
QFe=4(kW/m), αFe=80(W/mK),rI =1.5(m),rO =3.0(m), kO=10(W/m2K)
Iron(1m-t)

Iron shield (Duratec?)
Concrete shieldheat at rI
cooled at rO

QFerO
QFe
∆TO =ln +2πα Fe rI 2πrO kO= 5.5( K ) + 21.2( K ) = 27( K )Air flow: 40000(J/s)/1.0(J/g/K)/10(K) =200(m3/min)Radio activity of air ⇒ Oyama’s talk

Cooling system for Al wall
Final focusSection(TP-1.7m)
Primary coolingwater line
for magnet(FF section)

Underground machineroom for beam dump
(TP?m)

Machinebuilding forbeam dump
Primary cooling system (TP?m)Primary cooling system
for Decay volume
Decay for Decay volume(Dump side)(Targetside)
32°C

Underground machine room
(TP+2.7m)

volume360 litter/min

Buffer tank

35°C
23°C
120 litter/min

32°C
Buffer tank

Chiller
50kW

150kW

30°C
30°C
540 litter/min
30°C
3000
litter/min

1.15m3
35°C

32°C
Pump

Chiller
50kW

80°C
Pump

Primary cooling system
for Aluminum wall andupper/collimator ironshield

Magnet

35°C

30°C
480 litter/min

35°C

170kW
0.06m345°C 240 litter/min

32°C
360 litter/min

DP tank

Disposalline

Sparechiller
50kW
Water

Disposal line
800m3/20days

cooling system for target/hornbuilding of
2nd machine Surface
target stationbuilding(TP+10.8m)(TP+9.3m)

Pump
Chiller
50kW
Chiller
50kW

Underground machine room
(TP+2.7m)
60 litter/min

20kW
0.1m3
30 litter/min

for target

30 litter/min

10kW
0.2m3
30litter/min

for 1st horn

30 litter/min

10kW
0.2m3
30litter/min

for 2nd horn

30 litter/min

10kW
0.2m3
30litter/min

for 3rd horn

Buffertank

240 litter/min
150 litter/min

Sparechiller
50kW

Third water Secondary watercooling system cooling system

Primary water cooling system

Primary cooling system for target
in experiment

Undergroundmachine pit(TP+2.7m)

Service pit Target
area(TP+2.7m)(TP-1.7m)

Filters for
Degassingradioactivity system
30litter/min.

in maintenance

Secondarywater line

Target

Water

Pumps

Disposal to buffertank for DV

20kw
1 litter
Buffer tank

Air circulation/ventilation system
Always ventilating
Building

Fresh airInsidedouble-doorHEPAfilterStack

Filter for salt
Undergroundmachine room

Circulation in experiment
Cooling unit
Iron shieldcooling

Circulation in experiment

Ventilation inmaintenanceSchedule(our hope) Budget for TS
FY2003

FY2004

FY2005

FY2006

FY2007

FY2008Support for target Conceptual
designand horns

Basicprototype

DesignPrototype

Production

Installation

Conceptual
designBasicprototype

DesignPrototype

Production

Installation

RemotemaintenanceConceptual
designBasicprototype

DesignPrototype

Production

Installation

Cooling

Conceptual
designPrototype

DesignProduction

ShieldConceptual
designPrototype

DesignProduction

Building

Conceptual
designDesignHelium container
MockupInstallation
Installation
Construction

Summary•Conceptual design of Target Station finish soon.
•Building•Shielding•Cooling•Support•Maintenance•Realistic design, R&D work and prototyping will start.
•Construction will start in 2006 and end in 2008
if budget is approved.

Backup

Doseat targetarea(mSv/h)
Effective
Dose(mSv/h)

Effect of Aluminum wall
10 4

10 3

102IronFe
Na-24

AluminumAL~100mSv/h

10 1

10 0

10-1

10 -2

Na-22
1day

100 days

After one year irradiation

After one year
irradiation

10 -3 -4 -3 -2 -1 0
10 10 10 10 10 10 1 10 2 10 3 10 4 10 5Time after(hour)Time irradiation(Hour)

Aluminum wall reduces surface dose by ~1/10 at maintenance.
Cost vs Performance should be studied.

Cooling system for Target/Horn
To 2nd machinebuilding

Heat exchange
Primary cooling water system
Secondary cooling water system
Third cooling water system

Primary cooling system for horn
Underground Service pit Targetmachine pit (TP+2.7m) area
(TP+2.7m)(TP-1.7m)

in experiment
Filters forDegassing
radioactivity system

30litter/min.
Secondaryin maintenancewater line

1st horn

WaterPumps

Disposal to buffertank for DV

10kw
200 litter
Buffer tank

Very rough cost estimation•Building: ~4.3M$(Underground) + ~0.8M$(Surface)•Crane: ~0.5M$•Concrete shield blocks: 1600m3×~300$/m3 = ~0.5M$•Iron shield blocks: 4000ton×(200~300)$/ton = 0.8~1.2M$•Helium container: 160ton×~1000$/ton×~2? = 0.3M$?
•Aluminum wall: 120ton×~3000$/ton×~2? = 0.7M$?
•Support system of horn: ~0.1M$?×4 = ~0.4M$?
•Air cooling & ventilating system: ?
•Water cooling system: ?
•1M$ ~ 1×108 Yen•Excluding horns and target

Control of airService pit(230m3)
Machine room(140m3)
Keep out in experiment•In experiment:circulation•In maintenance:ventilation

Helium container:

Keep out forever•Circulation of Helium

Stock room for radioactive parts
Keep out forever•In experiment :circulation•In maintenance:ventilation

Building (8300m3):•Ventilation through stackTop view of target station
22m

Underground machine room

Trailer

Area for removed shields

beam

Area forspare horns

Storage for radioactive material

33m

Operation room
for maintenanceArea forentrance control

Underground machine room
•ターゲット
一次冷却水（0.01m3,28kBq/cc）のポンプ＋タンク、熱交換器(~30kW)、二次冷却水のポンプ＋タンク•ホーン
一次冷却水（0.6m3,5kBq/cc）のポンプ＋タンク、熱交換器(~30kW)、二次冷却水のポンプ＋タンク•鉄シールド＋アルミヘリウム箱
地下機械室
一次冷却水（数m3?,数kBq/cc?）のポンプ＋タンク、熱交換器(~200kW)
FF部（二次系はFF部と共通）•ディケイボリューム
一次冷却水（3m3,数kBq/cc）
放射化物保管庫のポンプ＋タンク、熱交換器(~200kW)（二次系はFF部と共通）
排水は地下機械室よりディケイボリュームを通って下流のDPタンクへ

DV空気・ヘリウムの放射化0.75MW20日運転後（反応断面積σ=30mb） 排気基準：5mBq/cc以下
場所

Neutronfluence(/p/cm2)

放射化(Bq/cc)

容量(m3)

トリチウム(Bq)

排気時間(h)上屋

1×10-19

4×10-14

8000

0.3

1

サービスピット

5×10-12

2×10-6

230

5×105

0.03

地下機械室

5×10-12

2×10-6330

7×1050.04放射化物保管庫

5×10-12

2×10-6780

1.6×1060.1

鉄シールド外面

1×10-10

4×10-538

1.5×1060.005

鉄シールド中間

1×10-8

4×10-333

1.3×1080.004

鉄シールド内面TSヘリウム

2×10-5828

2.2×1011

5.62×10-480?

135

1.1×1013?

270?

DVヘリウム5×10-520?

1600

3.1×1013?

800?

ヘリウムの断面積は1.2mb？（1/25？）

Neutrino target

Target0.75MW
beam360

1st Horn

2nd Horn

1510

2000

3rd Horn
2500

1400

900

Graphite rod•diameter:30mm, Length:900mm (80% interaction)•beam size: σr ~6mm
•fixed inside 1st horn
•20kw heat load: cooled by water⇒ Hayato’s talk tomorrow

鉄シールドブロック

Iron shield

水冷の場合、冷却管取付け

2.2mX2.2mX1m(36トン）
18個＝650トン
2mX1.5mX1m(23トン）
36個＝810トン
3mX1.5mX1m(34トン）
72個＝2430トン
冷却面（水冷又は空冷、２５０ｋW）
合計３９００トン
平成18年度製造、19年度据付