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Entry  Sun Feb 26 17:40:43 2012, tara, DailyProgress, optic, beam realignment after new seismic stack installation  IMG_0373.JPGIMG_0374.jpg
    Reply  Mon Feb 27 10:56:43 2012, tara, DailyProgress, optic, beam realignment after new seismic stack installation  
Message ID: 844     Entry time: Sun Feb 26 17:40:43 2012     Reply to this: 845
Author: tara 
Type: DailyProgress 
Category: optic 
Subject: beam realignment after new seismic stack installation  

I'm trying to re-align the beams to the cavities. Due to the new RTV springs for the seismic stack, the cavities' natural axes shift by ~1/4 " with respect to the previous position.

     I had to adjusted the height of the top mirror of the periscope before I could align and lock RCAV (visibility ~ 95%) again. The pictures below show the position of the current beam. With the previous setup, the beam position was almost at the center of the holes. Now, for RCAV, the axis shifts closer to the edge. RCAV might yaw with respect to the previous position. Left picture shows the incoming beam position, Right picture shows the outgoing beam position.

IMG_0374.jpgIMG_0373.JPG

      For ACAV, however, it seems that the position changes a lot and the beam clips on the outer edge of the top mirror before I can even find TEM00. I think I'll have to add a spacer between the mirror mount and the vertical plate in order to re align the beam.

     I think we can keep the stack position as it is for now, if I can lock both cavities and the transmitted beams can be adjusted on the breadboard for beat path. We might also have to increase the hole size on the insulation cap as well depending on where the beam position of ACAV will be.

 

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