Vacuum windows at JPARC Yoshikazu Yamada (KEK) T.Ishii, T.Iwashita, - - PowerPoint PPT Presentation

Vacuum windows at JPARC

Yoshikazu Yamada (KEK)

T.Ishii, T.Iwashita, M.Minakawa, Y.Oyama, H.Takahashi, et.al. 4th International Workshop on the Neutrino Beams and Instrumentation November 10, 2003

Contents

• Introduction
• Vacuum windows at hadron beam line

Helium gas cooling

• Vacuum windows at neutrino beam line

primitive discussion

Hadron & Neutrino beam lines

Neutrino beam line Hadron beam line 50 GeV PS

Neutrino beam line

Single turn fast extraction 8 bunches in 5µs 3.3x1014proton/spill Cycle: 3.53 sec.

Time(sec.)

0.7sec.

Hadron beam line

Slow extraction: 0.7 sec.

Windows in hadron beam line

Fast reaction valve

10-6~10-8 Torr Turbo & Ion pump 10-3 Torr Rotary pump 50GeV PS： 10-8 Torr

Window for T1-downstream

Container of T1-target (air and water inside) Beam dump (Low Pressure?) NP-hall Switch Yard

Window for T1-upstream

SY Vacuum window

Vacuum chamber :20cm-φ, SS or Al or Ti Connected by ‘Radial seal’

Window for Dump

SY vacuum window

• Separate vacuum in SY(10-3Torr) from one in 50GeV-PS (10-8Torr)
• Aluminum : 20cm-φ, 100µm-t
• Edge : cooled at 30ºC by water or air
• Average deposit: 3.5J/spill ⇒ Temperature rise : 16(K) (SS: 480(K) )

(MARS+ANSYS)

0.0E+00 2.0E+06 4.0E+06 6.0E+06 8.0E+06 1.0E+07 1.2E+07 2 4 6 8 10

R (cm) Deposit (W/m3)

Radius (cm) Deposit (W/m3)

σr ~ 1cm Aluminum window +16(K)

Time dependence of temperature

Aluminum Stainless Steel T>1 min. ： T=30 +16 ± 4 (ºC) T>20 min. ： T = 30 + 480 ± 10 (ºC)

Time(sec) Time(sec) Center Center Temperature(ºC) 60 60 30 46 30 300 Temperature(ºC)

Beam window for T1-target

Water Air Primary beam line:~10-3 Torr Vacuum chamber ~10-3 Torr

Upstream windows for T1 diameter:10cm Downstream windows for T1 diameter:30cm

He 1g/cm2 1m/s He T1 target

Double wall (SS or Al)

• cooled by He flow in gap
• gap: ~1cm
• remote maintenance

Beam axis

SS SS SS/Al SS/Al

T1 container

Upstream window for T1 (T1-U)

0.00 0.05 0.10 0.15 0.20 0.25 0.30 1 2 3 4 5

R (cm) t (cm)

0.0E+00 1.0E+08 2.0E+08 3.0E+08 4.0E+08 5.0E+08 1 2 3 4 5

R (cm) Deposit (W/m3)

Radius (cm) Deposit (W/m3)

σr ~ 2mm

Radius (cm) Thickness (cm)

100µm 2.5mm

SS window

• Separate vacuum of beam line (10-3Torr) from air(1atm) in T1 container
• SS/Al (beam-line side) and SS (T1 side) : 10cm-φ, variable thickness
• Cooled by He(1atm & 1m/s) between two walls
• Average deposit:10.2 J/spill on SS window

(9.2 J/spill if t=100µm)

Temperature of window T1-U

Natural convection : 10W/m2/K Forced convection : 100W/m2/K Outer edge : cooled to be 30ºC by water or air One surface : cooled by convection by Helium SS window +320(K) SS window +160(K) Temperature rise : 320 (K) Temperature rise : 160 (K)

Deformation/Stress of window T1-U

SS window 0.7mm SS window

• Max. stress due to pressure：

200MPa@center ＜Tensile strength:500MPa Deformation:0.7mm@center If t=0.1mm(uniform)

• deformation：

2.1mm

• Stress：

310MPa@center,1000MPa@edge

Helium cooling at KEK-B factory

He He Heat transfer coefficient 1g/s (6l/s, 1.7m/s)

• 120W/m2K(measured by U.Tsukuba)
• 164W/m2K(calculation)
• 220W/m2K(measured by IHI)

Water cooled Helium cooled Aluminum Aluminum Beryllium Double wall of Beryllium Water cooled Vacuum chamber for interaction point ~100W heat

Helium cooling system

He compressor He cooler He tank water pump water cooler

Downstream window for T1(T1-D)

0.00 0.10 0.20 0.30 0.40 0.50 0.60 5 10 15

R (cm) t (cm)

0.0E+00 5.0E+07 1.0E+08 1.5E+08 2.0E+08 2.5E+08 5 10 15

R (cm) Deposit (W/m3)

• Separate vacuum chamber (10-3Torr) from air(1atm) in T1 container
• SS/Al (beam-line side) and SS (T1 side) : 30cm-φ, variable thickness
• Cooled by He(1atm & 1m/s) between two walls
• Average deposit: 1060 J/spill on SS window

(115 J/spill if t=0.1mm) σr ~ 5mm 100µm 5mm

Radius (cm) Energy deposit (W/m3) Thickness (cm) SS window Radius (cm)

Temperature/stress of window T1-D

SS window 3.3mm SS window +170(K) Outer edge: cooled to be 80ºC Temperature rise: 170(K) @100W/m2K 810(K) @10W/m2K Deformation:3.3mm Stress due to pressure: 450MPa at center ~Tensile strength 500MPa

Window for beam dump

• Separate vacuum in beam line (10-3Torr) from air in beam dump
• Stainless Steel : 50cm-φ, variable thickness
• Simple wall or double wall with Helium cooling
• Average deposit: 136 J/spill (98 J/spill if thickness is 1mm-t)

. E + 2 . E + 5 4 . E + 5 6 . E + 5 8 . E + 5 1 . E + 6 1 . 2 E + 6 1 . 4 E + 6 5 1 1 5 2 2 5 R ( c m ) D e p

• s

i t ( W / m 3 )

. E + 1 . E

• 1

2 . E

• 1

3 . E

• 1

4 . E

• 1

5 . E

• 1

6 . E

• 1

5 1 1 5 2 2 5 R ( c m ) t ( c m )

Radius (cm) Radius (cm) Energy deposit on window (W/m3)

σr ~ 5cm

Thickness (cm)

1mm 5mm

Temperature/stress of window(dump)

SS window SS window +8(K) Deformation:5.7mm Stress due to pressure: 200MPa at R=20cm <Tensile strength 500MPa Outer edge: cooled to be 30ºC Temperature rise: 8(K) @100W/m2K 64(K) @10W/m2K

Preparation Section ARC Section (Super conducting) Final Focusing Section Target Station

PS vacuum window (?)

• Separate vacuum in PS&ARC&FF(10-6Torr)

from one in 50GeV-PS (10-8Torr)

50GeV PS

TS exit window(?) TS entrance window

Final focus Decay volume (Helium)

Helium container Target Station

Windows in neutrino beam line

Window in Preparation Section

0.0E+00 1.0E+07 2.0E+07 3.0E+07 4.0E+07 5.0E+07 2 4 6 8 10

R (cm) Deposit (W/m3)

σr ~ 6mm (smallest case)

• Separate vacuum in PS(10-6Torr) from one in 50GeV-PS (10-8Torr)
• 20cm-φ, Al 26µm-t(?) or SS 10µm-t(?) (0.01% loss) (realistic?)
• Edge : cooled at 30ºC by water or air
• Average deposit : 0.68J/spill ⇒ ∆T : Al:~14(K), SS:~520(K)
• But, ∆T by single spill ⇒ Al:~67(K), SS:~104(K)
• study on thermal stress and durability against heat cycle
• study with larger beam size

Al 26µm-t

Radius (cm) Deposit (W/m3) Al 26µm-t

+14(K)

Window for entrance of TS

0.0E+00 1.0E+07 2.0E+07 3.0E+07 4.0E+07 5.0E+07 6.0E+07 0.5 1 1.5 2 2.5

R (cm) Deposit (W/m3)

σr ~ 6mm

• Separate vacuum in PS(10-6Torr) from He gas (1 atm) in TS
• Aluminum : 5cm-φ、

1mm-t (can be thinner)

• Edge : cooled at 30ºC by water or air
• Average deposit : 34J/spill ⇒ ∆T ~18(K)
• But, ∆T by single spill ⇒ 82(K)
• study on thermal stress and durability against heat cycle
• double wall and Helium cooling?

Al 1mm-t

Al 1mm-t Radius (cm) Deposit (W/m3)

+18(K)

Summary

• We started to study on windows for 50GeV beam line.
• Average temperature rise and deformation/stress by

pressure were estimated by MARS+ANSYS

• Conduction cooling for aluminum windows for
• Switch Yard of hadron beam line
• Preparation Section of neutrino beam line (?)
• Forced convection cooling by helium gas for windows for
• Upstream/downstream of T1 target in hadron beam line
• Beam dump in hadron beam line
• Entrance window of neutrino target station (?)
• Exit window of neutrino target station (??)

Plan

• Study of thermal stress and shock wave
• Optimization of thickness
• Measurement of thermal transfer coefficient of He cooling
• Test production of windows and study durability
• Design and production of double wall window

with ‘Radial seal flange’ system developed by Y.Yamanoi et.al.

Proton beam He gas Double wall

‘Radial seal flange’

Backup

Hadron beam line in Switch-Yard

5 0G e Vリング 仮想取り出し点( E )

一次ビームラ イ ン （ A ラ イ ン）

h 1v 2 q 1 q 2 h 3 v 4 q 3 q 4 q 5 h 5 v 6 q 6 q 7 q 8 q 9 q A q 1 1 q 1 2 h 7 v 8

S M 1

h 1 3 q 1 1 q 1 2 h 1 3 q 1 3 q 1 4 q 1 5

T

v 1 4 h 1 5 q 1 6h 1 6 q 1 7q 1 8v 1 7 q 1 9 q 1 A

M P S M 1

S 1 S 2 S 3 S 4 S 5 S 6 S 7 S 8 S 9 S 1 S 1 1 S 1 2 S 1 3 S 1 3 S 1 4 S 1 5 S 1 6 S 1 7 S 1 8 S 2 S 1 9 S 2 1 S 2 2 S 2 3 ゲート バルブ ビームモニタ ー ラジアルシール ビーム膜 真空ポン プ

Fast reaction valve

SY Vacuum window

10-6~10-8 Torr Turbo & Ion pump (every 20m) 10-3 Torr Rotary pump (every 20m) 50GeV PS： 10-8 Torr 30m Vacuum chamber :20cm-φ, SS or Al or Ti Connected by ‘Radial seal’

Hadron beam line in NP-Hall

ゲート バルブ ビ ームモニタ ー ラ ジアルシール ビーム膜 真空ポンプ

Q 1 9 Q 1 A Q 1 B Q 1 C Q 1 D 第２ コ リ メ ータ 第１ コ リ メ ータ ２ ０ ０ ３ ． ３ ． ４ 改訂 S 2 3 S 2 4 S 2 5 S 2 6

Window for T1-upstream Window for T1-downstream Window for Dump

10-3 Torr 10-3 Torr Container of T1-target (air and water inside) 10m Beam dump (Low Pressure?)

Neutrino target station

Iron shield Helium container Machine room Service pit Stock room for activated parts 11m Iron shield Concrete blocks 40t crane Target & 1st horn Beam window 2nd horn 3rd horn Final focus Decay volume Concrete Beam window Ground level Baffle 22m 33m

T1 downstream window

• Diameter: ~30cm
• Vacuum side: Aluminum
• Air(T1) side: SS
• 0.1mm-t at center
• 5mm-t at edge (water cooled)
• Temperature rise of SS window at center

+170ºC (forced convection by He flow(~1m/s) : 100W/m2K) +810ºC (natural convection : 10W/m2K)

Remote maintenance for T1

shield motor water beam target beam Front view Side view

Maintenance work should be done at service space

• 1. Disconnect cables and

cooling tubes.

• 2. Detach vacuum flanges.
• 3. Replace shields with cask.
• 4. Detach shaft, disks and

upper plate, and move them to stock space.

• 5. Install new parts with cask.
• 6. Replace cask with shields.
• 7. Connect cables and tubes.

requires remote maintenance tools

3m

Remote vacuum sealing

Design specification

• Inner Diameter: ≥30cm
• Metal sealing
• Small leak:~1×10-10 Pa•m3/s
• Remote operation
• Operation time: 1~5 min.
• Small force required

Candidate

• Mechanical holding (V-block)
• Pillow seal
• Radial seal (under development)

Prototype of “Radial seal”

developed by Y.Yamanoi(KEK) , M.Tsuchiya(IHI Ltd) and Usui Kokusai Sangyou Kaisya Ltd.

Remote lifting Tools

Lifting tools from CERN and PSI

Magnet Crane

Specification

Up to 40t Short height Remote connection Video camera viewing Two or four points lifting Interlock for one-side lifting

Under design

Neutrino beam line

νµ beam of ~1GeV

Fast-extracted proton beam line

50GeV PS Super- Kamiokande

νµ→ νx disappearance νµ→ νe appearance

Decay volume Target station Beam dump

Target and secondary beam lines

K1.8 HR K1.1 K0 NP-Hall

Production target : T1

Rotating Nickel disks

• thickness: ~54 mm
• radius: ~24 cm
• cooled by water
• developed by Y.Yamanoi
• et. al.

Proton beam