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Entry  Fri May 28 21:32:32 2010, Alberto, Update, 40m Upgrading, MC alignment 
    Reply  Fri May 28 23:21:52 2010, Koji, Update, IOO, MC alignment 
       Reply  Mon May 31 00:10:18 2010, kiwamu, Update, IOO, MC alignment 
          Reply  Mon May 31 03:38:48 2010, Koji, Update, IOO, MC alignment MC_spot_centering.png
             Reply  Mon May 31 17:47:34 2010, kiwamu, Update, IOO, today's plan : MC alignment 
Message ID: 3019     Entry time: Mon May 31 00:10:18 2010     In reply to: 3013     Reply to this: 3020
Author: kiwamu 
Type: Update 
Category: IOO 
Subject: MC alignment 

  [Alberto, Kiwamu]

The MC alignment is getting better by steering the axis of the incident beam into the MC.

We found the beam spot on MC1 and MC3 were quite off-centered in the beginning of today's work. It had the coil gain ratio of 0.6:1.4 after running the A2L script.

In order to let the beam hit the center of the MC1 and MC3, we steered the bottom mirror attached on the periscope on the PSL table to the yaw direction.

And then we got better numbers for the coil gain ratio (see the numbers listed at the bottom).

For the pitch direction, there still are some rooms to improve because we didn't do anything with the pitch. It is going to be improved tomorrow or later.


Here are the amounts of off-centering on MC1 and MC3 after steering the axis. 

 C1:SUS- MC1_ULPIT_GAIN =  0.900445

C1:SUS-MC1_ULYAW_GAIN =  0.981212

C1:SUS-MC3_ULPIT_GAIN =  0.86398

C1:SUS-MC3_ULYAW_GAIN =   1.03221

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