An apparatus for high resolution field emission spectroscopy

We have constructed new apparatus for high resolution field emission spectroscopy. This apparatus, which we call HRFES system, consist of a new spectrometer, a computer controlled low-noise power supply, an extremely-high-vacuum chamber, and a new pressure gauge. The high resolution of better than 0.5 meV was realized by the new spectrometer. By using the HRFES system, we measured the energy distributions of field electrons emitted from tungsten (W) 〈310〉 and niobium (Nb) 〈111〉 tips at −193°C (80 K) and room temperature in the emission current region from 10−8 to 10−6 A. The high-intensity part of observed curves at emission of ∼ 10−8 A agreed with the calculated ones based on the Fowler-Nordheim theory, while there are discrepancies in two energy regions.