Solid state amplifiers are being used for linear accelerators at TRIUMF which are either being upgraded or under development. The Radioactive Ion Beam (RIB) facility at ISAC II which is being upgraded with additional 20 quarter wave superconducting bulk niobium cavities will employ twenty 141 MHz solid state amplifiers. A 650 MHz solid state amplifier for electron gun development and an 1.3 GHz...

At CERN a compact Quadrupole Resonator has been developed for the RF characterization of superconducting samples at different frequencies. In this paper, results from measurements on bulk niobium and niobium film on copper substrate samples are presented. We show how different contributions to the surface resistance depend on temperature, applied RF magnetic field and frequency. Furthermore, me...

Cryogenic molecular beam experiments show that the ferroelectric dipole moments of small niobium clusters with an even number of valence electrons n are typically greater than those with odd n. This is verified in alloy clusters NbNXM where X = Al, Au, O, Mn, Fe, and Co; N ≤ 100;M ≤ 3. Like in superconducting alloys, Mn doping quenches the effect while Al and Au enhance it, suggesting a relatio...

This paper presents a study of the reaction of thin film niobium/selenium multilayers as a function of layer thickness. Diffraction and calorimetry data show a distinct difference in reactions between films with layer thicknesses above and below 60 A. The thicker films are shown to nucleate NbsSe4 heterogeneously at the niobium-selenium interfaces. Thinner films form kinetically stable amorphou...

Binding energy of hydrogen in a ~100! niobium slab is investigated through molecular-dynamics simulations. We introduce a hydrogen-niobium interaction potential that contains an attractive as well as a repulsive part, which is valid for surface-diffusion calculations. Simulations for high and low temperatures ~compared with uDebye! are presented. For the former case, we found that the hydrogen ...

Superconducting thin films have the potential to improve the performance of particle accelerators. Before these thin films can be implemented, a systematic study on structureproperty correlations is necessary. Here, we present the characterization of niobium thin films deposited onto both ceramic and metallic substrates. In particular, the film microstructure and superconducting properties are ...

This work presents a new synthesis of nano-sized lithium niobate particles by a low temperature three steps procedure. The complete protocol implies a LiH induced reduction of NbCl5 followed by in situ spontaneous oxidation into low valence niobium nano-oxides. These niobium oxides are exposed to air atmosphere leading to pure Nb2O5 formation. Finally, the stable Nb2O5 is converted into lithium...

A calorimetric technique enables precise measurements of the surface resistance RS of superconducting samples. One of the devices exploiting this technique at multiple frequencies is the Quadrupole Resonator. Its measurement capabilities and limitations are discussed and compared with similar devices. Results on bulk niobium and niobium film on copper samples are presented. It is shown how diff...

High-resolution conductance measurements in niobium nanowires below the superconducting transition temperature are presented. Results are shown for a complete multistage elongation-compression cycle of a nanoscale contact. We focus on a bistability region which manifests itself as random telegraph noise. Density functional structural optimizations and conductance calculations using the non-equi...