Laterally resolved microwave surface-resistance measurement of high-T/sub c/ superconductor samples by cavity substitution technique

Devices for SRF material characterization

“…In order to measure the surface impedance of a sample surface, it is necessary to make the sample a part of a resonant structure. Such a sample could be a rod [20,21], a flat disc [20,[22][23][24][25][26][27][28][29][30][31][32][33][34] or just a small piece [20,35,36] inserted into the cavity inner surface. The cavity is then excited in a particular mode with the resonant frequency and Q 0 easily measurable, allowing one to calculate the surface impedance in a straightforward way [20, 22, 23, 25-30, 37, 38] based on average losses and differential measurements with calibrated samples.…”

Sensitivity of surface resistance measurement of HTS thin films by cavity resonator, dielectric resonator and microstrip line resonator

“…The surface resistance of HTS film deposited on 10 mm×10 mm is measured using a TE 011 mode of a cylindrical cavity resonator at 20 GHz by partial end-plate substitution technique (CPEPS) [2]. In this method, the sample is embedded at the center of the end-plate, through annular opening of 2d = 9.6 mm, of the copper cavity (diameter 2a = 22.42 mm and length L = 12.94 mm) having surface resistance R scu of metallic region.…”

“…In this method, the sample is embedded at the center of the end-plate, through annular opening of 2d = 9.6 mm, of the copper cavity (diameter 2a = 22.42 mm and length L = 12.94 mm) having surface resistance R scu of metallic region. The unloaded quality factor Q 0 of the cavity containing sample of surface resistance R s is derived using appropriate boundary conditions as [2] 1…”