# What are the largest thermal gradients achievable in a lab environment?

I am looking for a system capable of creating a gradient of $100\, \mathrm{K}/\mathrm{\mu \textrm{m}}$ on a $30\, \mathrm{\mu}\textrm{m}$ spacing of a system mounted on a Si-N membrane. My so-called nanoheater is not up to the task.

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Ahh... I was hoping this was a vague informal question. Having recently toured a toroidal fusion reactor, I can tell you where to find a $100K/\mu m$+ temperature gradient! –  NeuroFuzzy Jun 21 '13 at 22:16