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Entry  Mon Jun 14 22:16:08 2010, Jenne, Update, IOO, Mode scan after Mode Matching Telescope after_MMT.png
    Reply  Tue Jun 15 16:28:32 2010, kiwamu, Update, IOO, Mode Profile after Mode Matching Telescope newIOO_overlap_edit.png
       Reply  Tue Jun 15 19:24:25 2010, rana, Update, IOO, Mode Profile after Mode Matching Telescope 
          Reply  Fri Jun 18 21:45:39 2010, kiwamu, Update, IOO, Mode Profile after Mode Matching Telescope (Round 2) MMT20100618_edit.pngnewIOO_overlap_edit.png
             Reply  Fri Jun 18 22:12:29 2010, Alberto, Update, IOO, Mode Profile after Mode Matching Telescope (Round 2) 
Message ID: 3077     Entry time: Tue Jun 15 16:28:32 2010     In reply to: 3076     Reply to this: 3078
Author: kiwamu 
Type: Update 
Category: IOO 
Subject: Mode Profile after Mode Matching Telescope 

We obtained a good mode match overlap of 99.0% for the new IOO.

And if we move the position of MMT2 by another 10 cm away from MMT1, we will have 99.6% overlap. 

Yesterday Jenne and I put MMT2 on the OMC table. MMT2 was carefully put by measuring the distance between MMT1 and MMT2.

The position looked almost the same as that drawn on the CAD design.

After putting it we measured the profile after the MMT.

 

The attached figure shows the computed mode overlap according to the fitting result while changing the position of MMT2 in a program code.

The x-axis is the position of MMT2, the current position is set to be zero. The y-axis is the mode match overlap.

Right now the overlap is 99.0% successfully, but this is not an optimum point because the maximum overlap can be achieved at x=100 mm in the plot.

It means we can have 99.6% by moving the position of MMT2 by another 10 cm. This corresponds to an expansion of the MMT length.

If this expansion is difficult due to the narrow available space in the chamber, maybe staying of MMT2 at the current position is fine.

Attachment 1: newIOO_overlap_edit.png  91 kB  Uploaded Tue Jun 15 12:53:32 2010  | Hide | Hide all
newIOO_overlap_edit.png
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