4 research outputs found
Depth-resolved measurement of the Meissner screening profile in a niobium thin film from spin-lattice relaxation of the implanted -emitter Li
We report measurements of the Meissner screening profile in a Nb(300
nm)/AlO thin film using Li -detected nuclear magnetic
resonance (-NMR). The NMR probe Li was ion-implanted into the Nb
film at energies 20 keV, corresponding to mean stopping depths
comparable to Nb's magnetic penetration depth . Li's strong
dipole-dipole coupling with the host Nb nuclei provided a
"cross-relaxation" channel that dominated in low magnetic fields, which
conferred indirect sensitivity to the local magnetic field via the spin-lattice
relaxation (SLR) rate . From a fit of the data to a model
accounting for its dependence on temperature, magnetic field, and
Li implantation energy, we obtained a magnetic penetration depth
= 51.5(22) nm, consistent with a relatively short carrier
mean-free-path = 18.7(29) nm typical of similarly prepared Nb films. The
results presented here constitute an important step towards using Li
-NMR to characterize bulk Nb samples with engineered surfaces, which are
often used in the fabrication of particle accelerators.Comment: 16 pages, 4 figure
17th International Conference on RF Superconductivity
RF superconductivity is the key technology of accelerators for particle physics, nuclear physics and light sources. SRF 2015 covered the latest advances in the science, technology, and applications of superconducting RF. There was also an industrial exhibit during the conference with the key vendors in the community available to discuss their capabilities and products