Abstract
Shadowing is widely used for biological macromolecules and their complexes structure determination . It has been shown that tungsten shadowing produces fine granularity and good structural detail resolution. We have developed a working prototype of an electron beam evaporator (“electron gun“) based on the principle described by V. Vasiliev. The electron gun has characteristics that allow us to deposit high quality films of carbon or even pure tungsten. in addition we have constructed a prototype sample handling apparatus for freeze drying and shadowing. The prototype allows tilting of +/- 90° in 2° increments, rotation (if desired) at 6 rpm, controlled heating at a rate of 1-2° per min, and cooling using a liquid nitrogen trap attached to the device. The system is vacuumed by 480 1/sec maglev turbomolecular pump with scroll pump at the first stage. It produces oil-free vacuum in 2-5*10-7 torr range, which we believe, is sufficient for good quality shadowing.
Publisher
Cambridge University Press (CUP)
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