Investigation on Realization of High-Q Value and High Accelerating Gradient Superconducting Cavity via Furnace Baking Method

Abstract

The performance of superconducting radio-frequency cavities depends on niobium surface conditions. Recently, various surface treatments focused on heat treatment have been investigated to realize the high-Q value and high accelerating gradient cavities. We report the influence of a new heat treatment process called furnace baking on the performance of 1.3 GHz TESLA type superconducting radio-frequency cavities made of niobium. Furnace baking is simpler than the previously reported heat treatment method, therefore it is easy to apply to the cavities. We find that the Q value increases after furnace baking at temperatures ranging from 250 to 400°C and Q behavior to the accelerating gradient are similar to nitrogen doped cavities. Furthermore, we find a significant difference in the surface resistance between baking temperatures ranging from 200 to 800°C.