Open Question: Is the Plug Feasible?
The most consequential open question is whether a coil can hold 26.49 T at the design bore; today it is overstressed 3 to 3.9 times.
The question, sharply
Can a real magnet produce and survive 26.49 T at the bore the design needs? Today the answer in simulation is no — the coil is overstressed 3–3.9x. This is the question most likely to reshape the machine or the schedule.
Possible resolutions
- A materials and structure combination that reaches margin at 26.49 T
- A field/bore re-optimisation that lowers peak stress
- A confinement scheme that tolerates a lower plug field
- An honest conclusion that the design point must move
Why we state it as open
We do not assume the plug is solvable at the current point. Stating it as an open question — with a real chance the design point changes — is more honest than presenting the 26.49 T plug as settled. The prototype program exists to answer it.
We state this as a genuine question, with a real possibility that the answer forces the design point to move, because that is the honest posture. A study that assumed the plug solvable at 26.49 T would be asserting the very thing it has not shown. The prototype program exists to answer the question in hardware, and we will report whichever way it answers.