II. The 2nd Generation Voltage Application Mechanisms


This exploded view shows the internal geometry of the rotational docking piece. Unlike the previous docking piece, this new design has two embedded circular electrodes (red). The radii of these concentric electrodes have been determined such that the electrodes do not get their ways in between the surface contacts between the upper docking plate and the lower docking plate (bright green). This way voltage application mechanism does not compromise the overall thermal conductivity. The previous coldfinger housed a thin layer of mica layer in between the docking piece and coldfinger geometry which resulted in significant increase in the sample surface temperature. 

The concentric electrodes are insulated from the copper base by three sheets of mica blocks (white). The electrodes, when electrically live, transmit voltage differential to the sample surface through two C- shaped sample clamps (not shown in the picture) which will be located in the middle of each of linear slots. The blue gears is used to translate the sample stage (not shown) which will be inserted between two top covers (violet). Once everything is assembled, it would look like,


Notice that the circular electrodes maintain contact with the two side electrodes for two pi angle rotation. Since the voltage mechanisms exist separate from the main geometry, they do not increase the overall thermal resistance. between the cooling rod (to be inserted into the coldfinger from the top left) and eventually to the sample (bright blue).

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