chris.mueller@LIGO.ORG - posted 22:17, Wednesday 09 January 2013 (5063)
IOT2L Table Build
[Keita K., Cheryl V., Kiwamu I., Paul F., Chris M.] Tonight we began aligning the MC refl beam onto IOT2L. The first problem which we ran into is that the beam exiting the chamber is slightly low on the viewport but very low on the table enclosure hole. Although this isn't inherently a problem, we decided to take a look around to see if the alignment had changed. In particular, we checked the back reflected beam from the input viewport to HAM 1 which had moved down by ~5 mm relative to some previous wall markings. We also aligned the beam to a photodiode and checked the IMC visibility which was roughly 15 %. Cheryl informed us that drifts in the PSL have commonly caused problems for her in the past so we started our realignment by tuning the top periscope mirror and using the IMC visibility as a fiducial. This brought the visibility to ~30 %. Afterwards, we re-tuned the mode cleaner mirrors in all by less than ~200 counts each which brought the visibility back to ~80 %. We likely could have done better but decided that this was good enough to lock. As of now the IOT2L table has all of the optics on it, and refl is aligned to the PDH pd, but the WFS/camera path has not been aligned. The table still needs to be fixed in place with the screws on the legs. We are leaving the LVEA is laser hazard for the night although the shutter and viewports are closed.
