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Entry  Thu Oct 20 01:40:33 2011, Koji, Summary, SUS, MC2 Misaligned 2:27PM on Wednesday MC2_misalign.png
    Reply  Thu Oct 20 18:57:35 2011, Suresh, Summary, SUS, MC2 Misaligned 2:27PM on Wednesday 
       Reply  Fri Oct 21 02:36:44 2011, Suresh, Summary, SUS, MC2 Misaligned 2:27PM on Wednesday : MC Realigned 
       Reply  Fri Oct 21 02:57:38 2011, Suresh, Summary, SUS, MC2 Misaligned 2:27PM on Wednesday : cause traced 
          Reply  Fri Oct 21 09:08:33 2011, steve, Update, SUS, MC2 Misalignment mc2.jpg
             Reply  Wed Nov 2 10:04:05 2011, steve, Update, SUS, MC2 chamber anchoring tightened 
Message ID: 5718     Entry time: Fri Oct 21 02:57:38 2011     In reply to: 5716     Reply to this: 5719
Author: Suresh 
Type: Summary 
Category: SUS 
Subject: MC2 Misaligned 2:27PM on Wednesday : cause traced 

Quote:

Quote:

There looks some activity at around MC2 on Wednesday afternoon.
It caused the misalignment of MC2. Misalignment was not found in MC1/3.

It seems that the incident beam on the MC was aligned in the evening.
This increased the MC transmission but it is vibible that the spot on MC2 is shifted from the center.

We need an action on this issue tomorrow in the daytime.

 

I am working on fixing this.  You might some strange stuff going on in the control room screens.  Pls ignore it till I am done.

 

While chatting with Jenne I learnt that some substantial amount of work had taken place yesterday around the MC2 chamber.  This was associated with the relocating of seismometers.  ref elog

I reiterate what is well known for quite sometime:  MC2 table is not well isolated from the ground.  And we should not approach this chamber unless absolutely necessary. I have blocked off the area around it which we should avoid.  It is a serious waste of time and effort to realign the MC each time the MC2 table decides to settle into a new position.

Steve tells me that the mild-steel frame supporting the chamber+MC2_table sits with two legs on one concrete slab while the other two legs sit on another one.   The frame is also quite weak without sufficient gussets or cross connects.  The next time we have a major shutdown we must replace this frame with a more sturdy one which sits on one slab (preferably the one on which the rest of the MC sits).

Till we improve this mounting, I suggest that we avoid that area as much as possible.

 

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