The temperature distribution in a field ion microscope (FIM) specimen heated simultaneously by thermal radiation, the imaging gas, and an energetic beam of charged particles was calculated in the steady-state approximation employing a realistic model for the FIM specimen. The variation in crosssectional area of the specimen with distance along the shank was taken into full account. The possibility of a temperature change caused by the thermoelastic effect was also considered and shown not to be of importance. The value of ∆Tmax (maximum temperature difference along the length of the specimen) was ~2·5×10–3°k at the best image field (4·4 v Å–1) for tungsten imaged at 15°k with helium gas. Hence, it was concluded that the act of observing a specimen by field ion microscopy did not perturb appreciably the temperature of the tip. It was also shown that a rather high energy density beam of energetic particles was required to produce a significant value of ∆Tmax.
ASJC Scopus subject areas
- Physics and Astronomy(all)