1. Neutrino target station at JPARC Contents Introduction Radiation (detail: talked by Oyama) Support system & maintenance Cooling system Schedule 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

2. 1st Horn2nd Horn 3rd Horn Fast-extracted proton beam line Neutrino beam line and target Target Station Decay volume Beam dump 50GeV PS Target Carbon target: 30mm- ,900mm-L beam size: σ r ~6mm beam to SK 0.75MW beam

3. Neutrino target station 22m Iron shield Helium container Machine room Service pit Storage for radioactive material 11m 33m Iron shield Concrete blocks 40 ton crane Target & 1st horn Beam window 2nd horn3rd horn Final focus Decay volume Concrete shield Beam window Ground level Baffle 22m

4. Iron:2.2m concrete wall : 20cm-t Iron:1.5m Concrete:4.4m Concrete:1m < 12.5  Sv/h@floor of surface building < 0.25  Sv/h @out of the control area fence Concrete: 4.5m Concrete:3.6m Shielding and radiation level < 5mSv/h @boundary of concrete 0.75MW operation detail  Oyama’s talk confirmed by MARS

5. Residual dose Aluminum wall ~0.65(0.17) Sv/h Upper iron shield Outer : 22(16)  Sv/h Inner : 0.56(0.42) Sv/h Floor of service pit ~0.1(0.07) μSv/h Service pit Machine room One (seven) day cooling after one year operation (by MARS) detail  Oyama’s talk

6. Side view of target area Baffle Target+ 1st horn 2nd horn 3rd horn Iron shield Concrete shield Iron shield Concrete shield Service pit Bus bar Aluminum wall Bus bar Window Helium container Support of horn Collimator for DV 15m 2.2m 1m1m

7. Front view of target area 1st horn Iron shield Concrete shield Iron shield Concrete shield block Service pit Transformer Aluminum wall Bus bar Helium container Support of horn Concrete shield block Area for additional shields for 4MW storage for radioactive material Underground machine room 3m3m 6m6m

8. 1st horn Iron shield Iron shield Bus bar Helium container Concrete shield block Helium container 3m(W)  6m(H)  15m(L), 5cm-thick iron wall Filled by Helium gas (1-atm, 130m 3, ~99%) Reduce Tritium production : ~1/25?  ~30mb for Air,  ~1.2mb for He Tritium production after 200 days operation: Air:800Bq/cm 3, He:30Bq/cm 3 Ventilation time after 200 days operation Air:110days, He:5days (ventilation: 8000m 3 /hour, regulation:5mBq/cm 3 ) 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 Support of horn Iron shield Concrete shield support alignment support hear

10. Exchange of the target/ horn storage of radioactive materials top view Cross-sectional view 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. Ground level

11. Exchange of the target A) If horn is broken, scrap target and horn. B) If target is broken; 1)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 : ~170 kW on Aluminum, 40kW on Iron Heat load on Al-wall/Fe-shield Energy deposit (W/m) Aluminum Fe(1st 20cm) Fe(2nd 20cm) Iron shield Concrete shield MARS

13. Water pipe for Aluminum wall (option for 4MW) Cooling for Aluminum wall Temperature rise in Al wall Q Al =17/8(kW/m),  L= 3/2(m),  A ｌ =240(W/mK), A=0.2(m 2 ) Iron shield Concrete shield 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/m 2 K),  T=3.7(K) 、  P=0.11(kg/cm 2 ) Radio activity of water  Oyama’s talk

14. Air cooling surface for iron shield Outer surface (Default) Middle surface (Option for 4MW) Inner surface (Option for 4MW) Cooling for Iron shield Water pipe for upper iron shield Iron(1m-t) heat at r I cooled at r O Temperature rise in iron shield Q Fe =4(kW/m),  Fe =80(W/mK), r I =1.5(m),r O =3.0(m), k O =10(W/m 2 K) Iron shield (Duratec?) Iron shield Concrete shield Air flow: 40000(J/s)/1.0(J/g/K)/10(K) =200(m 3 /min) Radio activity of air  Oyama’s talk

15. Cooling system for Al wall 150kW 1.15m 3 170kW 0.06m 3 32  C 360 litter/min Buffer tank 32  C Chiller 50kW Chiller 50kW Spare chiller 50kW Underground machine room (TP+2.7m) Underground machine room for beam dump (TP?m) Final focus Section (TP-1.7m) Machine building for beam dump (TP?m) Primary cooling system for Decay volume (Target side) Primary cooling system for Decay volume (Dump side) Buffer tank Pump Decay volume Primary cooling water line for magnet (FF section) Magnet DP tank Disposal line Water Disposal line 800m 3 /20days 30  C 540 litter/min 35  C 30  C 3000 litter/min 80  C 30  C 32  C 360 litter/min 35  C 32  C 23  C 120 litter/min 30  C 480 litter/min Primary cooling system for Aluminum wall and upper/collimator iron shield 35  C 45  C 240 litter/min

16. for target for 1st horn 20kW 0.1m 3 30 litter/min 10kW 0.2m 3 30litter/min 10kW 0.2m 3 30litter/min 10kW 0.2m 3 30litter/min 60 litter/min 150 litter/min Buffer tank 240 litter/min Pump Chiller 50kW Chiller 50kW Spare chiller 50kW Underground machine room (TP+2.7m) Surface building of target station (TP+10.8m) 2nd machine building (TP+9.3m) cooling system for target/horn Third water cooling system Primary water cooling system Secondary water cooling system for 2nd horn for 3rd horn

17. water line Secondary Disposal to buffer tank for DV Pumps Filters for radioactivity Degassing system Water Buffer tank Underground machine pit (TP+2.7m) Service pit (TP+2.7m ) Target area (TP-1.7m) Target 20kw 1 litter Primary cooling system for target 30litter/min. in experiment in maintenance

18. Circulation in experiment Always ventilating Ventilation in maintenance Stack HEPA filter Filter for salt Cooling unit Fresh air Air circulation/ventilation system Circulation in experiment Building Underground machine room Iron shield cooling Inside double-door

19. FY2003FY2004FY2005FY2006FY2007FY2008 Support for target and horns Conceptual design Basic prototype DesignPrototypeProductionInstallation Helium container Conceptual design Basic prototype Design PrototypeProductionInstallation Mockup Remote maintenance Conceptual design Basic prototype DesignPrototypeProductionInstallation Cooling Conceptual design PrototypeDesignProduction Installation Shield Conceptual design PrototypeDesignProductionInstallation Building Conceptual design Design Construction Schedule Budget for TS(our hope)

20. 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.

21. Backup

22. Effect of Aluminum wall Aluminum wall reduces surface dose by ~1/10 at maintenance. Cost vs Performance should be studied. After one year irradiation 1day 100 days Time after irradiation (hour) ~100mSv/h Dose at target area (mSv/h) Aluminum Iron

23. Secondary cooling water system Third cooling water system Primary cooling water system Heat exchange To 2nd machine building Cooling system for Target/Horn

24. water line Secondary Disposal to buffer tank for DV Pumps Filters for radioactivity Degassing system Water Buffer tank Underground machine pit (TP+2.7m) Service pit (TP+2.7m ) Target area (TP-1.7m) 1 st horn 10kw 200 litter Primary cooling system for horn 30litter/min. in experiment in maintenance

25. Very rough cost estimation Building: ~4.3M$(Underground) + ~0.8M$(Surface) Crane: ~0.5M$ Concrete shield blocks: 1600m 3  ~300$/m 3 = ~0.5M$ 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  10 8 Yen Excluding horns and target

26. Service pit(230m 3 ) Machine room(140m 3 ) Keep out in experiment In experiment:circulation In maintenance:ventilation Control of air Building (8300m 3 ): Ventilation through stack Helium container: Keep out forever Circulation of Helium Stock room for radioactive parts Keep out forever In experiment :circulation In maintenance:ventilation

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

28. Underground machine room ターゲット 一次冷却水（ 0.01m 3,28kBq/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（ 0.6m 3,5kBq/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 一次冷却水（数 m 3 ?, 数 kBq/cc? ） のポンプ＋タンク、熱交換器 (~200kW) （二次系は FF 部と共通） ディケイボリューム 一次冷却水（ 3m 3, 数 kBq/cc ） 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 放射化物保管庫 地下機械室 FF 部 DV

29. 空気・ヘリウムの放射化 場所 Neutron fluence (/p/cm 2 ) 放射化 (Bq/cc) 容量 (m 3 ) トリチウ ム (Bq) 排気時間 (h) 上屋 1  10 -19 4  10 -14 80000.31 サービスピット 5  10 -12 2  10 -6 230 5  10 5 0.03 地下機械室 5  10 -12 2  10 -6 330 7  10 5 0.04 放射化物保管庫 5  10 -12 2  10 -6 780 1.6  10 6 0.1 鉄シールド外面 1  10 -10 4  10 -5 38 1.5  10 6 0.005 鉄シールド中間 1  10 -8 4  10 -3 33 1.3  10 8 0.004 鉄シールド内面 2  10 -5 828 2.2  10 11 5.6 TS ヘリウム 2  10 -4 80?135 1.1  10 13 ? 270? DV ヘリウム 5  10 -5 20?1600 3.1  10 13 ? 800? 0.75MW20 日運転後（反応断面積  30mb ） 排気基準： 5mBq/cc 以下 ヘリウムの断面積は 1.2mb ？（ 1/25 ？）

30. Neutrino target Graphite rod diameter:30mm, Length:900mm (80% interaction) beam size: σ r ~6mm fixed inside 1st horn 20kw heat load: cooled by water  Hayato’s talk tomorrow 1st Horn2nd Horn 3rd Horn Target 0.75MW beam

31. 鉄シールドブロック 2mX1.5mX1m (23 トン） 36 個＝ 810 トン 3mX1.5mX1m (34 トン） 72 個＝ 2430 トン 2.2mX2.2mX1m (36 トン） 18 個＝ 650 トン 合計３９００トン 平成 18 年度製造、 19 年度据付 冷却面 （水冷又は空冷、２５０ｋ W ） 水冷の場合、 冷却管取付け Iron shield