W(310) cold-field emission characteristics reflecting the vacuum states of an extreme high vacuum electron gun
- Hitachi High-Technologies Corporation 882, Ichige, Hitachinaka-shi, Ibaraki-ken 312-8504 (Japan)
- Kagami Memorial Laboratory for Materials Science and Technology, Waseda University, 2-8-26 Nishi-Waseda, Shinjuku-ku, Tokyo 169-0072 (Japan)
An extremely high vacuum cold-field electron emission (CFE) gun operating at pressures ranging from {approx}10{sup -8} Pa to {approx}10{sup -10} Pa was constructed. Only the CFE current emitting from W(310) surfaces revealed the existence of a 'stable region' with high current angular density just after tip flash heating. In the 'stable region,' the CFE current was damped very slowly. The presence of non-hydrogen gas eliminated this region from the plot. Improvement of the vacuum prolonged the 90% damping time of the CFE current from {approx}10 min to 800 min. The current angular density I{sup Prime} of CFE current was 60 and 250 {mu}A/sr in the 'stable region' for total CFE currents of 10 and 50 {mu}A, respectively. These results were about three times larger than I{sup Prime} when measured after the complete damping of the CFE current. The CFE gun generated bright scanning transmission electron microscopy images of a carbon nanotube at 30 kV.
- OSTI ID:
- 22105351
- Journal Information:
- Review of Scientific Instruments, Vol. 84, Issue 1; Other Information: (c) 2013 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
Similar Records
Spatial and temporal characteristics of a vacuum-arc rail-gun plasma
An ion gun with relatively high yield at low pressure (<10/sup -3/ Pa)