SCIENCE SPIN-OFFS

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At present, none of the “high Tc” superconducting materials are suitable for RF applications. Shortcomings of these materials arise due to their underlying physics as well as their bulk mechanical properties not being amenable to fabricating accelerator cavities. However, depositing films of promising materials onto other mechanically amenable cavity materials may provide a viable option for exotic materials serving SRF applications.

There is work to get quality factors up to 200 billion. Ambient magnetic field, if trapped in the penetration depth, leads to the residual resistance and therefore sets the limit for the achievable quality factors in superconducting niobium resonators for particle accelerators. Here, we show that a complete expulsion of the magnetic flux can be performed and leads to: (1) record quality factors Q?over?200 billion up to accelerating gradient of 22 MV/m; (2) Q?~?30 billion at 2?K and 16 MV/m in up to 190 mG magnetic fields. This is achieved by large thermal gradients at the normal/superconducting phase front during the cooldown. The findings open up a way to ultra-high quality factors at low temperatures and show an alternative to the sophisticated magnetic shielding implemented in modern superconducting accelerators.


https://www.nextbigfuture.com/2017/06/if-emdrive-is-real-and-scales-with-q-factor-then-we-get-almost-star-trek-level-technology.htmltry