Published online by Cambridge University Press: 06 June 2002
A monochromatic Fe beam is generated by heated supersonicexpansion of argon seeded with Fe vapor. At a nozzle temperatureof 1930 K and 800 torr argon inlet pressure the Fe beam has anaxial velocity spread of 8% and intensity of 3 × 1015s−1 sr−1, corresponding to a deposition rate of 10 nm/h at 150 mm from the nozzle. The two-chamber alumina crucibles arechemically stable for liquid Fe. With 400 mm3 Fe we haveoperated for more than 200 hours without reloading. The powerconsumption at 1930 K is 750 W. Temperature stability at constantpower (without feedback) is better than 30 K. The source isintended for deposition of nanostructures by laser focusing of theFe beam. The small axial velocity spread virtually eliminates theincrease in focal spot size due to chromatic aberration.