Abstract
The construction and the vibrational performance of a low vibration laboratory for microscopy applications comprising a 100 ton floating foundation supported by passive pneumatic isolators (air springs), which rest themselves on a 200 ton solid base plate, are discussed. The optimization of the air spring system leads to a vibration level on the floating floor below that induced by an acceleration of 10 ng for most frequencies. Additional acoustic and electromagnetic isolation is accomplished by a room-in-room concept.
Highlights
Modern microscopes with a spatial resolution reaching deep into the nanoscale or even into the picometer scale are known to be sensitive to external vibrations
Scanning electron microscopes and transmission electron microscopes are sensitive to horizontal vibrations, while scanning probe microscopy techniques are much more sensitive to vertical vibrations since picometer resolution is mainly desired in the vertical direction
While we have considered the transfer function above in order to characterize the efficiency of a vibration isolation system, the actual vibration level at the unit to be isolated from vibrations is the relevant quantity
Summary
Modern microscopes with a spatial resolution reaching deep into the nanoscale or even into the picometer scale are known to be sensitive to external vibrations. A standard approach in scanning probe microscopy is to combine a stiff construction of the microscope itself with a vibration isolation using springs and an eddy current damping. At low temperatures a spring suspension prevents good thermal coupling to the microscope or, in the case that large magnetic fields are present, an eddy current damping cannot be used. In these cases either the whole microscope chamber or even the whole laboratory in which the electron microscope or the low temperature scanning probe microscope is operated should be isolated from external vibrations, such as ground vibrations and acoustic vibrations.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
