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Entry  Fri Jan 27 06:07:47 2012, kiwamu, Update, LSC, glitch hunting 
    Reply  Fri Jan 27 17:16:05 2012, kiwamu, Update, LSC, hypothetical glitch scenario 
    Reply  Thu Feb 16 03:47:16 2012, kiwamu, Update, LSC, glitch table 
       Reply  Wed Feb 22 01:53:57 2012, kiwamu, Update, LSC, update on glitch table 
Message ID: 6231     Entry time: Fri Jan 27 06:07:47 2012     Reply to this: 6235   6284
Author: kiwamu 
Type: Update 
Category: LSC 
Subject: glitch hunting 

I went through various IFO configurations to see if there are glitches or not.

Here is a summary table of the glitch investigation tonight. Some of the cells in the table are still not yet checked and they are just left blank.

IFO configuration  Yarm
Xarm
MICH
Half PRMI
low finesse PRMI
PRMI (carrier)
PRMI (sideband)
DRMI
AS55 NO NO NO   up conversion noise glitch glitch glitch
REFL11 NO NO NO   up conversion noise
glitch glitch glitch
REFL33 NO NO NO   - glitch glitch glitch
REFL55 NO NO NO   up conversion noise
glitch glitch glitch
REFL165 NO NO NO   - glitch glitch glitch
POX11 - NO NO     glitch glitch glitch
POY11 NO - NO     glitch glitch glitch
POP55 - -            
                 

 

        Low finesse PRMI      

The low finesse PRMI configuration is a power-recycled MIchelson with an intentional offset in MICH to let some of the cavity power go through MICH to the dark port.

To lock this configuration I used ASDC plus an offset for MICH and REFL33 for PRCL.

The MICH offset was chosen so that the ASDC power becomes the half of the maximum.

In this configuration NO glitches ( a high speed signal with an amplitude of more than 4 or 5 sigma) were found when it was locked.

Is it because I didn't use AS55 ?? or because the finesse is low ??

Also, as we have already known, the up conversion noise (#6212) showed up -- the level of the high frequency noise are sensitive to the 3 Hz motion.

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