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Entry  Wed Jun 2 01:47:28 2010, Alberto, Kiwamu, Update, IOO, mode measurement of new input optics afterMMT1.pngbeam_profile.pngMMT1_.dat.zipinside_vac_2.png
    Reply  Wed Jun 2 03:50:03 2010, Koji, Update, IOO, mode measurement of new input optics 
       Reply  Thu Jun 3 13:14:27 2010, kiwamu, Update, IOO, mode measurement of new input optics inside_vac_2.png
          Reply  Thu Jun 3 14:01:51 2010, kiwamu, Update, IOO, mode measurement of new input optics check_measurement_edit.png
             Reply  Thu Jun 3 14:13:20 2010, Jenne, Update, IOO, mode measurement of new input optics 
    Reply  Thu Jun 3 14:40:28 2010, Alberto, Kiwamu, Update, IOO, mode measurement of new input optics 
       Reply  Tue Jun 8 00:38:22 2010, Koji, Kiwamu, Update, IOO, improved Gaussian beam in new IOO 2010-6-7_2.png
          Reply  Fri Jun 11 14:31:04 2010, kiwamu, Update, IOO, mode matching of new IOO profile_MMT.pngdist_MMO.png
Message ID: 3045     Entry time: Thu Jun 3 14:13:20 2010     In reply to: 3044
Author: Jenne 
Type: Update 
Category: IOO 
Subject: mode measurement of new input optics 

Quote:

I checked the measured data of the mode profile which was taken on the last Tuesday.

For the vertical profile,

the plot shows a good agreement between the expected radius which is computed from the past measurement, and that measured on the last Tuesday.

However for the horizontal profile,

it looks like being overestimated. This disagreement may come from the interference imposed on the Gaussian spot as we've been worried. 

So we should solve this issue before restarting this mode matching work.

 - The next step we should do are;

checking the effect of MMT1 on the shape of the beam spot by using spare MMT1

 

NOTE:

The expected curve in the attached figure were computed by using the fitted parameter listed on the entry 2984 .

In the calculation the MMT1 is placed at 1911mm away from MC3 as we measured.

And the focal length of MMT1 is set to be f=-2500mm.

 When / if you use the other MMT1 mirror, make sure to take note whether or not it says "SPARE" on it in pencil.  I don't remember if it's the other MMT1, or if it's one of the MMT2's that says this.  The mirror was baked, so it's okay to use in the vacuum, however it's the one which was dropped on the floor (just prior to baking), so any discrepancies measured using that optic may not be useful.  I don't know how strong the CVI coatings are to scratches resulting in being dropped from a ~1m height.  Bob and I didn't see any obvious big scratches that day, but that doesn't necessarily give it a clean bill of health. 

The optic labeled "SPARE" should NOT be used as the final one in the IFO.

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