Transcript NSTX Workshop Notes.ppt

issues
• 40 min. rep. rate
• Fabrication of flex sections
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Water jet cut copper
Copper flat cable
Others – electroform brazed straps
Shape
OOP support
Action: will start at short pulse so rep rate will
only be a concern later. Consider upgrades for
shorter rep rate if affordable.
Need to understand reqmts. & behavior
better – more analyses.
A.J. Tuck in Conn. For
electroform braze; alternative
wire EDM
• Testing of flex section candidates.
– How to simulate OOP loads
• Reaction of out of plane load
– Structure details
– Need for a flex section between flag
& outer TF leg
• TF outer leg support
– Is it worth making any changes or is
the present adequate?
A key detail needed for success!
Consider a large diaphragm for
torque reaction/thermal expansion.
TF single turn joint model
• PF 4/5
– Struts between them are needed
• VV
– Mid band stresses are too high by a factor of ~2 – will need to
weld a reinforcement band around the inside of the VV.
– Will need to check weld stresses at port extensions and possibly
reinforce the welds
• Modeling:
– HM’s current model has the old skinny CS – this could send too
much torque to the VV Need to add the new CS details
– Need to update the global model with the reinforced umbrella
structure, new CS, flex regions, etc.
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Consider a 12 turn TF design to create space.
TF copper
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Is the currently proposed conductor viable to be fabricated?
What is the fallback?
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Fabricate in 2 halves, machine colant groove, bond the halves together like C-Mod.
OH coils
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Leads
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Is it reasonable for the worst-case condition to be a design condition?
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Disruption loads
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Possibly have a different set of allowables for these “off normal” conditions
How to handle impact loads – do accelerometer studies on NSTX.
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PF coils
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TF joint heating
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Are there any conditions that put the coils in hoop compression with the possibility of buckling? Should check.
Need to study heat diffusion from joint interface.
Should do EM current diffusion calculations\
Need to adequately validate the joint design with testing at high currents and multiples of operating current.
Investigate other high current joint concepts
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Multilam, button contacts, felt metal, etc.
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What current density should we be targeting?
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Maybe check with high current switchgear manufacturers to see fi they have a solution.
Do measurements of deflections on NSTX to benchmark the analyses.
Analyze the castings in detail, adding “prying” action which may open casting halves.