Cooling situation

WFS starts up fine. Cooling line is closed because yesterday's leak has not been fixed, so we can keep the unit on for just short intervals.

Pupil wobbling check

I try again to measure the pupil wobbling. It is not possible to keep all four pupils illuminated, because the PSF goes from one pupil to the next, even when modulation 8V@200Hz. So in the end the measure is the same as yesterday's: a single pupil remains illuminated the whole way, and its wobbling is about 5 pixels.


Best cube position for LUCI

The cube holder is asymmetric, one side has been machined into a wedge in order to minimise vignetting on LUCI. The angle to correctly position the wedge towards LUCI has been measured to:

+92.2 degrees from homing

and it's the same position used in the board setup to send the light directly into the W unit.

Cube holder with wedge in front, seen from the LUCI side:


Small bar mirror alignment measurement

We mount the small bar using the references on the AGW metal beams. The mirror appears to be well-centered. Greg mounts the laser tracker and a reference point that is illuminated by the small bar mirror in reflection. Then the LUCI-facing flange is measured to have a reference surface. At this point we measure the mirror surface, and it comes out at about 0.3 degrees off. After tilting the mirror with the two micro-adjusters and iterating a few times, we get down to 0.0016 degrees = 5.7 arcsec.

Note: getting this low (last step was from 0.003 to 0.0016) required moving the micro-adjuster by a very tiny amount.

Laser tracker setup: IMG_20160204_113852.jpg

IRTC measurement

Greg measures the IRTC and the dichroic angle comes out as 15.33 +/- 0.04 degrees. This is rather different from the correct angle.

A further data reduction on the measurement of the two AGW flanges gives an improved result of 0.0007 +/ 0.0008 degrees, which is just about 3 arcsec.

-- AlfioPuglisi - 04 Feb 2016

Topic revision: r3 - 05 Feb 2016, AlfioPuglisi
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