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Entry  Wed Sep 7 22:41:44 2011, frank,tara, DailyProgress, , Two cavities are in the same chamber P1040900.JPG
    Reply  Thu Sep 8 20:53:17 2011, tara, DailyProgress, RefCav, frequency difference 
       Reply  Fri Sep 9 01:45:40 2011, Frank, DailyProgress, RefCav, frequency difference 
       Reply  Fri Sep 9 01:53:21 2011, Frank, DailyProgress, RefCav, frequency difference 
       Reply  Fri Sep 9 22:53:32 2011, frank, tara, DailyProgress, RefCav, frequency difference 
    Reply  Mon Oct 3 23:54:19 2011, frank, tara, DailyProgress, , re mode matching 
       Reply  Tue Oct 4 23:20:57 2011, frank, tara, DailyProgress, , re mode matching 
Message ID: 667     Entry time: Wed Sep 7 22:41:44 2011     Reply to this: 669   691
Author: frank,tara 
Type: DailyProgress 
Category:  
Subject: Two cavities are in the same chamber 

   We put two cavities in the same chamber. Next, we will measure the frequency difference between the two cavities when they have the same temperature to determine which frequency we need for the second AOM.

 

P1040900.JPG

Before we put the stack back in to the chamber, we measured Q from two modes of the stack(with cavities on it).

The modes are longtitudinal motion (translation along the beam line) and horizontal transverse motion [see this entry]. Other modes i.e. pitch, yaw die away too fast to be measured with ring down measurement.

The cavities' mirrors were checked and cleaned. ACAV's mirrors had a trace of smudge which is now cleaned.

Since the pendulum suspensions were removed, the cavity's height is reduced from 7" to 6" above the table. The periscope's height were adjusted accordingly.

The beam is aligned to RCAV, the visibility is ~85%, it decreases because the position of the cavity's height changes.

Now I'm trying to align the beam to ACAV. Once the beam aligned, we can lock the beam and measure what is the differential length of the two cavities, hence the frequency.

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