Field emission from crystalline niobium

Study of Secondary Electron Emission from Niobium at Cryogenic Temperatures

...................................................................................................................... iii LIST OF FIGURES ............................................................................................................ v LIST OF TABLES............................................................................................................. ix ACKNOWLEDGEMENTS.......

Effect of band structure on field emission of crystalline graphite

V L Katkov and V A Osipov Joint Institute for Nuclear Research, Bogoliubov Laboratory of Theoretical Physics, 141980 Dubna, Moscow region, Russia Abstract The field emission of crystalline AAA graphite is studied within a simple analytical approach with account of the exact dispersion relation near the Fermi level. The emission current is calculated for two crystal orientations with respect to ...

Field Emission and Thermal Breakdown in Superconducting Niobium Cavities for Accelerators

Field emission and thermal breakdown are the main mechanisms limiting the accelerating gradient of niobium radio-frequency cavities. Diagnostic tools to study these mechanisms include quality measurements, thermometry, and microscopy. Results presented here demonstrate that micron-size, conducting particles are the source of field emission. Thermal breakdown is caused by a variety of defects su...

Rapid and controlled electrochemical synthesis of crystalline niobium oxide microcones

We demonstrate the fabrication by anodization of niobium oxide microcones, several microns long, from aqueous solutions of 1 wt% hydrogen fluoride (HF) with varied sodium fluoride (NaF) concentration (0–1 M). Raman spectroscopy and x-ray diffractometer analysis revealed the as-grown microcones to be crystalline Nb2O5−x with preferred (1 0 0) and (0 1 0) orientations. The overall Nb2O5−x formati...

Field Emission from Graphene Nanosheets