Revision 1

Superseded · first revision · record

Title: Can a Nb3Sn cavity exceed the gradient of the best niobium cavities
Plain: The goal of Nb3Sn is to go beyond niobium, but so far niobium still holds the gradient record. The question is whether any Nb3Sn cavity can beat it.
Precise: Determine whether a Nb3Sn-coated 1.3 GHz elliptical cavity can sustain $E_{\mathrm{acc}}>0.45\,\mathrm{MV}/\mathrm{cm}$ ($B_{\mathrm{pk}}>1900\,\mathrm{G}$) at any temperature with $Q_{0}>1e10$, or whether intrinsic film properties (grain boundaries, thin-film thermal limits) forbid it.
Settled by: A Nb3Sn cavity test exceeding the Nb record gradient, or a demonstrated intrinsic bound below it.
Kind: well-posed
Answer type: yes-no
References: (empty)
Literature status: open
Status note: (empty)
Posed since: (empty)