Explosive cladding around obstacles

Erik Carton PhD

EPNM 2012, Strasbourg

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International Thermo-nuclear Experimental Reactor

ITER

ITER being build at Caderache, France

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Major Radius 6.2mPlasma Minor Radius 2.0mPlasma Volume 840m3

Plasma facing wall 850 m2

PFW materials Be, W, C/CPlasma Current 15.0MAToroidal Field on Axis 5.3TFusion Power 500MWPower Amplification >10 

Components that can be made using explosive processing

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Vacuum Vessel parts (VV)60 mm thick stainless steel 316 L (IG)

Plasma facing wall and divertorBe and W on Cu (alloy) and Stainless steel

Triangular supportCu (pure) on Stainless steel (316 IG)

Triangular support (40° section)

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Detail of the triangular supportStainless steel 60 mm

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2000 mm

1000

mmStub key

Diameter 300 mm

Simulation of detonation around an obstacleAutodyn 2D VoD = 3 km/s

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Autodyn 2D simulation of cladding around obstacle

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Autodyn 2D simulation of cladding around obstacle

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Autodyn 2D simulation of cladding around obstacle; Virtual VoD behind obstacle

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150 200 250 300 350 400 450

r (mm)

Def

f (km

/s)

Experiment: cladding around an obstacle

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Cladding result: non-bonding behind obstacle

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Potential solutions

• Reduce reflection using low impedance coating on stub-key

• Line initiation from the obstacle periphery

• Bi-layer explosive behind obstacle

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Simulation of detonation around an obstacleAutodyn 2D VoD = 3 km/s and 7 km/s

Sin α = Dclad/Ddetonation cord

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α

α

Simulation of detonation around an obstacleAutodyn 2D VoD = 3 km/s and 7 km/s

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Simulation of detonation around an obstacleAutodyn 2D VoD clad = 3 km/s

VoD cord = 7 km/s

Ratio = 0.43

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Line initiation from the obstacle peripheryExperimental set-up

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VoD clad = 3.6 km/sVoD cord = 7 km/sRatio = 0.5

Line initiation from the obstacle peripheryExperimental result

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Bi-layer explosive behind the obstacleExperimental result using detonation cord (VoD= 7 km/s)

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Cladding around 3 obstaclesExperimental set-up using powder explosives

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Detonation cord D=7 km/sPowder explosive D=5.5 km/s

Cladding explosive D=2.2 km/s

Bi-layer explosive behind the obstacleExperimental result using 5.5 km/s powder explosive

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VoD clad = 2.2 km/sVoD powd = 5.5 km/sRatio = 0.4

Conclusions

• Cladding around one (or more) obstacle is possible

• Solution 1: Line initiation (radial detonation from the obstacle)

• Real line initiations are not easily obtained

• Solution 2: Bi-layer explosive

• Best for round obstacles

• Minimizes detached zone area

• Enables multiple obstacle passage!

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