PARTICLE-OPTICAL APPARATUS INCLUDING A LOW-TEMPERATURE SPECIMEN HOLDER

摘要

In an electron microscope it is sometimes important that specimens can be studied at a very low temperature (for example, that of liquid helium). In the case of known specimen holders the specimen is cooled by supplying the cooling medium via a bore in the specimen holder; this causes thermal drift of the removed specimen holder each time when a specimen is exchanged, and also an acoustic coupling (i.e. transfer of vibrations) exists with the dewar vessel connected to the specimen holder. In accordance with the invention, the specimen is arranged on the end (20) of the specimen holder (7) by means of a separate transport unit (13, 36) so that it is not necessary to remove the specimen holder (7) in order to exchange a specimen, with the result that the specimen holder is not heated. Moreover, the coupling to the cold source (22, 28) can take place via a flexible cooling conduit (30) which extends directly to the end (20) to be cooled and may be permanently connected thereto, thus avoiding the transfer of vibrations. 00000