Neutrino target station at JPARC

1
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

2
Neutrino beam line and target

• Target
• Carbon target 30mm-f,900mm-L
• beam size sr 6mm

0.75MW beam

Fast-extracted proton beam line
Target Station
Decay volume
Beam dump
n beam to SK

50GeV PS
3
Neutrino target station
22m
33m
40 ton crane
11m
Ground level
Concrete blocks
22m
Service pit
Final focus
Beam window
Iron shield
Machine room
Decay volume
Helium container
Beam window
Concrete shield
Baffle
Storage for radioactive material
Iron shield
Target 1st horn
2nd horn
3rd horn
4
Shielding and radiation level
fence
concrete wall 20cm-t
lt 12.5mSv/h_at_floor of surface building
lt 0.25mSv/h _at_out of the control area
Concrete 4.5m
lt 5mSv/h _at_boundary of concrete
Concrete1m
Iron2.2m
0.75MW operation
Iron1.5m
Concrete3.6m
confirmed by MARS
Iron1.5m
Concrete4.4m
detail ? Oyamas talk
5
Residual dose
One (seven) day cooling after one year
operation (by MARS)
Floor of service pit 0.1(0.07) µSv/h
Machine room
Service pit
Upper iron shield Outer 22(16) µSv/h Inner
0.56(0.42) Sv/h
Aluminum wall 0.65(0.17) Sv/h
detail ? Oyamas talk
6
Side view of target area
15m
Service pit
Helium container
Bus bar
Bus bar
Bus bar
1m
Concrete shield
Iron shield
2.2m
Collimator for DV
Support of horn
Target 1st horn
2nd horn
Aluminum wall
Baffle
3rd horn
Window
Iron shield
Concrete shield
7
Front view of target area
Concrete shield block
Service pit
Helium container
Underground machine room
Bus bar
Transformer
Concrete shield block
Iron shield
storage for radioactive material
Support of horn
Area for additional shields for 4MW
1st horn
Aluminum wall
6m
Iron shield
3m
Concrete shield
8
Helium container

• 3m(W)?6m(H)?15m(L), 5cm-thick iron wall
• Filled by Helium gas (1-atm, 130m3, 99)
• Reduce Tritium production 1/25?
• s30mb for Air, s1.2mb for He
• Tritium production after 200 days operation
• Air800Bq/cm3, He30Bq/cm3
• Ventilation time after 200 days operation
• Air110days, He5days
• (ventilation 8000m3/hour, regulation5mBq/cm3)
• Reduce corrosion by NOx 1/100?
• 20cm thick Aluminum wall in target area
• reduce surface dose by 1/10 at maintenance

9
Support system of horn
Concrete shield
Iron shield
support hear
Support of horn
support alignment
10
Exchange of the target/ horn

• Upper Iron and concrete shields are removed.
• Highly radioactivated target/horn are moved under
  ground-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.

Cross-sectional view
Ground level
top view
storage of radioactive materials
11
Exchange of the target

• A) If horn is broken, scrap target and horn.
• B) If target is broken
• Scrap target and horn.
• or
• 2) Replace broken target with new one in the horn
• i) at the storage for radioactive material.
• or
• ii) at the beam line.

All works should be done remotely.
12
Heat load on Al-wall/Fe-shield
Heat load 170 kW on Aluminum, 40kW on Iron
Concrete shield
MARS
Aluminum
Fe(1st 20cm)
Iron shield
Fe(2nd 20cm)
Energy deposit (W/m)
Iron shield
13
Cooling for Aluminum wall
Water pipe for Aluminum wall
Concrete shield
Temperature rise in Al wall QAl17/8(kW/m), L
3/2(m), aAl240(W/mK), A0.2(m2)
Iron shield
Water flow 170(kJ/s)/4.2(J/g/K)/10(K)/8 30(Litte
r/min.)(?8) 1-inch tube Re32000, k4860(W/m2K),
? DT3.7(K)?DP0.11(kg/cm2)
Iron shield
Radio activity of water ? Oyamas talk
14
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 QFe4(kW/m),
aFe80(W/mK), rI 1.5(m),rO 3.0(m), kO10(W/m2K)
Iron shield (Duratec?)
Concrete shield
Air flow 40000(J/s)/1.0(J/g/K)/10(K) 200(m3/min)
Radio activity of air ? Oyamas talk
15
Cooling system for Al wall
Underground machine room for beam dump (TP?m)
Machine building for beam dump (TP?m)
Underground machine room (TP2.7m)
Final focus Section (TP-1.7m)
Primary cooling system for Decay volume (Dump
side)
Primary cooling system for Decay volume (Target
side)
Primary cooling water line for magnet (FF
section)
Decay volume
32?C 360 litter/min
35?C
Buffer tank
23?C 120 litter/min

32?C

150kW 1.15m3
Chiller 50kW

Buffer tank

30?C
32?C

30?C 540 litter/min

Chiller 50kW
Pump
35?C

80?C

30?C 3000 litter/min


32?C 360 litter/min

Pump
Disposal line
Primary cooling system for Aluminum wall
and upper/collimator iron shield
Spare chiller 50kW



Magnet
DP tank
Water
35?C
35?C
170kW 0.06m3
Disposal line 800m3/20days

30?C 480 litter/min



45?C 240 litter/min
16
cooling system for target/horn
Underground machine room (TP2.7m)
Surface building of target station (TP10.8m)
2nd machine building (TP9.3m)
for target
20kW 0.1m3 30 litter/min
60 litter/min

Buffer tank
Pump
10kW 0.2m3 30litter/min
for 1st horn
30 litter/min

Chiller 50kW

240 litter/min

150 litter/min
Chiller 50kW
10kW 0.2m3 30litter/min

for 2nd horn

30 litter/min
Spare chiller 50kW


10kW 0.2m3 30litter/min
for 3rd horn
30 litter/min
Third water cooling system
Secondary water cooling system

Primary water cooling system
17
Primary cooling system for target
Target area (TP-1.7m)
Underground machine pit (TP2.7m)
Service pit (TP2.7m)
in experiment
Filters for radioactivity
Degassing system
30litter/min.
in maintenance
Secondary
water line
Water
Target 20kw 1 litter
Pumps
Buffer tank
Disposal to buffer tank for DV
18
Air circulation/ventilation system
Always ventilating
Fresh air
Building
Stack
HEPA filter
Inside double-door
Filter for salt
Underground machine room
Ventilation in maintenance
Circulation in experiment
Cooling unit
Iron shield cooling
Circulation in experiment
19
Schedule
Budget for TS
(our hope)
20
Summary

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

21
Backup
22
Effect of Aluminum wall
Iron
Aluminum
100mSv/h
Dose at target area (mSv/h)
1day 100 days
After one year irradiation
Time after irradiation (hour)
Aluminum wall reduces surface dose by 1/10 at
maintenance. Cost vs Performance should be
studied.
23
Cooling system for Target/Horn
To 2nd machine building
Heat exchange
Primary cooling water system
Secondary cooling water system
Third cooling water system
24
Primary cooling system for horn
Service pit (TP2.7m)
Underground machine pit (TP2.7m)
Target area (TP-1.7m)
in experiment
Filters for radioactivity
Degassing system
30litter/min.
Secondary
in maintenance
water line
1st horn 10kw 200 litter
Water
Pumps
Buffer tank
Disposal to buffer tank for DV
25
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?(200300)/ton
  0.81.2M
• 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

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Control of air

• Building (8300m3)
• Ventilation through stack

• Service pit(230m3)
• Machine room(140m3)
• Keep out in experiment
• In experimentcirculation
• In maintenanceventilation

• Helium container
• Keep out forever
• Circulation of Helium

• Stock room for radioactive parts
• Keep out forever
• In experiment circulation
• In maintenanceventilation

27
Top view of target station
22m
Underground machine room
Area for removed shields
Area for spare horns
beam
Operation room for maintenance
Trailer
Storage for radioactive material
Area for entrance control
33m
28
Underground machine room

• ?????
• ?????(0.01m3,28kBq/cc)????????
• ????(30kW)?????????????
• ???
• ?????(0.6m3,5kBq/cc)????????
• ????(30kW)?????????????
• ?????????????
• ?????(?m3?,?kBq/cc?)
• ????????????(200kW)
• (????FF????)
• ?????????
• ?????(3m3,?kBq/cc)
• ????????????(200kW)
• (????FF????)
• ??????????????????????????DP????

29
??????????
????5mBq/cc??
0.75MW20????(?????s30mb)
?????????1.2mb?(1/25?)
30
Neutrino target

• Graphite rod
• diameter30mm, Length900mm (80 interaction)
• beam size sr 6mm
• fixed inside 1st horn
• 20kw heat load cooled by water
• ? Hayatos talk tomorrow

31
Iron shield
?????????
?????? ??????
2.2mX2.2mX1m (36??) 18?650??
2mX1.5mX1m (23??) 36?810??
3mX1.5mX1m (34??) 72?2430??
??? (???????250kW)
??3900?? ??18?????19????