1 Infrastructure at RAL Iouri Ivaniouchenkov, RAL MICE Collaboration meeting @ CERN, 29 March 2003.

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Infrastructure at RAL

Iouri Ivaniouchenkov, RAL

MICE Collaboration meeting @ CERN, 29 March 2003

2MICE Collaboration meeting @ CERN, 29 March 2003

Scope of presentation

• MICE solenoid mode : First results from magnetic simulation done by Jim Rochford

• Infrastructure : Hydrogen system diagram

• Layout : Status

3MICE Collaboration meeting @ CERN, 29 March 2003

Magnetic field profile for the final MICE stage

4MICE Collaboration meeting @ CERN, 29 March 2003

Solenoid mode : Field profile

Current densities as in stage 6

Current densities adjusted

5MICE Collaboration meeting @ CERN, 29 March 2003

Fringe fields for the MICE final stage

Fringe fields for final MICE: 5 gauss - R~6800

mm, Z~13400 mm

6MICE Collaboration meeting @ CERN, 29 March 2003

Solenoid mode: Fringe fields

Fringe fields for modified solenoid mode: 5 gauss - R~14900 mm, Z~21000 mm

Fringe fields for solenoid mode: 5 gauss -

R~14200 mm, Z~19900 mm

7MICE Collaboration meeting @ CERN, 29 March 2003

Fringe fields: Magnetic shielding

BH curve for 4.6 Stainless steel -Annealed

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

1 10 100 1000 10000 100000 1E+06

H(A/m)

B(T

)

Flux lines from unshielded coils (MICE Stage 6)

Flux lines from shielded coils with a cylindrical, 10mm thick steel shield, D=10m.

8MICE Collaboration meeting @ CERN, 29 March 2003

Fringe fields: Magnetic shielding

00.00050.001

0.00150.002

0.00250.003

0.00350.004

0.00450.005

0.00550.006

0.00650.007

0.0075

4.5 4.7 4.9 5.1 5.3 5.5

Field radially at Z=0 (m)

Bm

od (

T)

No shielding

10mm

5mm

3mm

5 gauss

Field detail in the shield region for the different thickness of steel cylinder modelled.

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MICE magnetic field: Conclusion

MICE Collaboration meeting @ CERN, 29 March 2003

• MICE will produce magnetic field which extends outside experimental hall:

Configuration 5 Gauss Line

Final MICE R~6800 mm, Z~13400 mmSolenoid mode R~14200 mm, Z~19900 mmModified solenoid mode R~14900 mm, Z~21000 mm

• Magnetic simulations are under way. First results show that shielding can be achieved by using steel cladding in the hall.

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Infrastructure : Hydrogen system

11MICE Collaboration meeting @ CERN, 29 March 2003

Hydrogen system design

Hydrogen supply and safety system

(as copied from M.Green’s paper)

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14 K Hefrom Cold box

H2 Gas bottle

Liquid level gauge

LH2 Absorber

Vacuum

Vacuum vessel

LHe Heat exchanger

12 litre Buffer tank

P

PFill valve

Large vacuum tank

Volume: 84 m3 (for all 3 absorbers)Pressure < 0.1 mbar

VP VP

Vent outside flame arrester

Hydrogen flow and safety system(based on Mike Green’s diagram)

19 K Window

70 K Safety window

Vent valve

1.7 bar

2.1 bar

N2 Purge systemP

P P VP Vacuum pumpBursting diskPressure relief valveValve

Pressureregulator

Pressuregauge

Non-return valve

18 K Heto Compressorvia Radiation shield

MICE Collaboration meeting @ CERN, 29 March 2003

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Hydrogen flow and safety system(another approach used in the RAL hydrogen target systems)

P P VP Vacuum pumpBursting diskPressure relief valveValve

Pressureregulator

Pressuregauge

18 K Heto Compressorvia Radiation shield

14 K Hefrom Cold box

Liquid level gauge

LH2 Absorber

Vacuum

Vacuum vessel

LHe Heat exchanger

12 litre Buffer tank

Internal Window

70 K Safety window

H2 Gas bottle

P

PFill valve

Hydrogen tank

Volume: 11 m3

Pressure > 0.1 bar

Vent outside flame arrester

He / N2 Purge system

Non-return valve

Vent outsideflame arrester

Vent valve

Vent valve

1.7 bar

2.1 bar

H2 Detector

H2 Detector

P

P

PP

Evacuated vent buffer tank

Volume:

VP

P

VP

X 2X 2

VP

14MICE Collaboration meeting @ CERN, 29 March 2003

Hydrogen flow and safety system:Comparison of two approaches

• Design philosophy ask Mike Closed system : - absorber and hydrogen tank compose one single volume; - hydrogen is either in gas tank (as gas) or in absorber (as liquid); - pressure is always higher then atmospheric

M.Green’s Approach RAL’s Approach

• Absorber working conditions T LH2 = 19 K => P>1.1 bar abs => P =0.63 bar abs T LH2 > 20.8 K

• Absorber filling from hydrogen gas tank /bottle from hydrogen tank

• Absorber empting to vacuum tank then venting to air to hydrogen tank then can be re-used

15MICE Collaboration meeting @ CERN, 29 March 2003

Hydrogen supply and safety system design: Questions

For whatever approach we choose there is a general question :

one common hydrogen system OR 3 independent hydrogen systems ?

Common system: - only one vent tank but is very large (80 m3) => too difficult to locate near absorbers - less equipment needed

Advantages Disadvantages

Independent systems: - less hydrogen in each system -more equipment needed => more safe scenario => more expensive

- absorbers operate independently => flexibility

16MICE Collaboration meeting @ CERN, 29 March 2003

Hydrogen supply and safety system design: Next steps

• Decide which approach to use for hydrogen system design => Define a flow diagram and main components

• Work out a layout => Try to fit all components into the experimental hall

• Fix conceptual design in the appropriate document (e.g. MICE Note)

• Start engineering design

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MICE layout

Drawings for experimental hall plus ISIS control room

• AutoCAD drawing is finished by Tony Jones• ProE 3D drawing is done

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MICE layout: 2D Model

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MICE layout : 3D Model

MICE Collaboration meeting @ CERN, 29 March 2003

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• Collect information about all sub-systems

(structure, main components with their dimensions)• Try to fit everything using AutoCAD drawing• Continue working on the magnetic shielding using 3D model

MICE Collaboration meeting @ CERN, 29 March 2003

MICE layout: Next steps