Testing and Simulation of the SRF Wafer Test Cavity for the Characterization of Superconductors and Heterostructures

Abstract

The wafer test cavity, designed at Texas A&M University, has been constructed and tested at Thomas Jefferson National Accelerator Facility. The mode structure, quality factor and coupling methods have been investigated. The TE_(011) mode has been located at 1.886492 GHz and the quality factor has been measured from room temperature to 2K. The measured quality factor at 2.7K is found to be 3.96x10^(8). Simulations of the cavity have been performed using Comsol Multiphysics and Mathematica to demonstrate the cavities potential as a test bed for superconducting materials, such as Heterostructures. The results of the experimental measurements are incorporated into the simulations to show that a Radio Frequency magnetic field of 162 mT can be placed on a sample of superconducting material, giving 81% of the BCS critical magnetic field for niobium.