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Entry  Fri Sep 9 16:16:59 2011, kiwamu, Update, IOO, spot positions on MC mirrors (in-vac) 
    Reply  Fri Sep 9 20:52:59 2011, kiwamu, Update, IOO, spot positions on MC mirrors (in-vac) 
Message ID: 5373     Entry time: Fri Sep 9 20:52:59 2011     In reply to: 5371
Author: kiwamu 
Type: Update 
Category: IOO 
Subject: spot positions on MC mirrors (in-vac) 

The spot positions on the MC mirrors were readjusted.

All the amount of the off-center became smaller than 2 mm, which meet requirements of the beam clearance on the Faraday.

 

    Feb 26 2011      May 08 2011 Aug 2 2011  Aug 10 2011 (in air) Aug 14 2011 (in air)

Aug 23 2011 (in air)

 Sep 9 2011 [NEW] Sep 9 2011
MC1 pit [mm]   1.6   1.9  1.93 -0.858 -0.2 0.1354  -1.55  0.22
MC2 pit [mm]   6.4   9.0 9.03 -0.844 -0.8 -0.2522  -2.28  -0.34
MC3 pit [mm]   1.4   2.0 2.01 -1.03 -0.1 -0.1383  -1.8 -0.21
MC1 yaw [mm]   -1.5   -1.7 -1.72 -0.847 -1.1 -1.0893  -0.02 -1.15
MC2 yaw [mm]   1.0   0.2 0.178 0.582 0.6 0.7122  3.52 0.07
MC3 yaw [mm]   -1.3   -1.9 -1.87 -1.06 -1.1 -1.5587  -2.145 -1.07

 

 In order to improve the MC1-YAW and MC3-YAW spot positions, the angle of the incident beam has to be shifted by approximately 1/100 rad.

However it turned out to be very difficult to introduce such amount of angle only with the steering mirrors on the PSL table since we have to keep the same translation while changing the angle.

 

Quote from #5371

The obtained spot positions are quite bad and roughly at 2-3 mm level. We have to realign the beam axis and the MC mirrors.

 

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