A Gold cavity resonator resonating at 10 GHz is fully coated using $$2 \mu m$$ YBCO (Yttrium Barium Copper Oxide) material and operating at boiling temperature of liquid nitrogen.
What is the Skin Depth of RF at this frequency?
Assume $$\sigma_{A \mu} = 4e 7$$ Siemens/meter at cavity operating temperature.

A

$$2 \mu m$$

B

$$\left(\frac{2.5}{\pi}\right) \mu m$$

C

$$0 \mu m$$

D

None of the above