Selection of ETMs
Of the four ETMs (5,6,7 and 8) that are with us Koji gave us two (nos. 5 and 7) for use in the current assembly. This decision is based on the Radius of Curvature (RoC) measurements from the manufacturer (Advanced Thin Films). As per their measurements the four ETMs are divided into two pairs such that each pair has nearly equal RoC. In the current case, RoCs are listed below:
The discrepancy between the measurements from these two companies leaves us in some doubt as to the actual radius of curvature. However we based our current decision on the measurement of Advanced Thin Films.
Assembly of ETMs
We drag wiped both the ETMs (5 and 7) and placed them in the Small Optic Gluing Fixture. The optics are positioned with the High Reflectace side facing downwards and with the arrow-mark on the Wire Standoff side (big clamp). We then used the microscope to position the Guide Rod and the Wire Standoff in the tangential direction on the ETMs (step 4 of the procedure specified in E010171-00-D)
We will continue with the rest of the assembly tomorrow.