Vortex-penetration field at a groove with a depth smaller than the penetration depth

Abstract

Analytical formula to evaluate the vortex-penetration field at a groove with a depth smaller than penetration depth is derived, which can be applied to surfaces of cavities or test pieces made from extreme type II superconductors such as nitrogen-doped Nb or alternative materials like Nb3Sn or NbN.

3 pages, 1 figure, the 27th Linear Accelerator Conference, LINAC14, Geneva, Switzerland, 31 August - 5 September, 2014