Application of Counter-wound Multi-arm Spirals in HTS Resonator Design.
Taylor L JohnstonArthur S EdisonVijaykumar RamaswamyNicolas FreytagMatthew E MerrittJeremy N ThomasJerris W HookerIlya M LitvakWilliam W BreyPublished in: IEEE transactions on applied superconductivity : a publication of the IEEE Superconductivity Committee (2022)
Significant sensitivity improvements have been achieved by utilizing high temperature superconducting (HTS) resonators in nuclear magnetic resonance (NMR) probes. Many nuclei such as 13 C benefit from strong excitation fields which cannot be produced by traditional HTS resonator designs. We investigate the use of double-sided, counter-wound multi-arm spiral HTS resonators with the aim of increasing the excitation field at the required nuclear Larmor frequency for 13 C. When compared to double-sided, counter-wound spiral resonators with similar geometry, simulations indicate that the multi-arm spiral version develops a more uniform current distribution. Preliminary tests of a two-arm resonator indicate that it may produce a stronger excitation field.