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Entry  Mon Aug 13 15:31:09 2012, steve, Update, General, larger optical tables at the ends ETMYtable.jpgETMY4X3.jpg
    Reply  Mon Aug 13 18:00:30 2012, jamie, Update, General, larger optical tables at the ends 
       Reply  Tue Aug 14 15:58:44 2012, Jenne, Update, General, Translation to English: larger optical tables at the ends 
    Reply  Wed Aug 15 16:01:47 2012, steve, Update, General, larger optical tables at the ends ? bottleneck.jpg
       Reply  Wed Aug 22 11:41:20 2012, steve, Update, General, grout plate for optical table at the ends IMG_1561.JPG08231201.PDF
          Reply  Thu Sep 27 19:03:06 2012, Manasa, Update, 40m Upgrading, New ETMX layout - Version 1.0 ETMX_OldNew.png
             Reply  Thu Sep 27 20:05:57 2012, Koji, Update, 40m Upgrading, New ETMX layout - Version 1.0 
                Reply  Fri Sep 28 07:49:30 2012, Steve, Update, 40m Upgrading, New ETMX layout - Version 1.0 
Message ID: 7179     Entry time: Tue Aug 14 15:58:44 2012     In reply to: 7163
Author: Jenne 
Type: Update 
Category: General 
Subject: Translation to English: larger optical tables at the ends 

Quote:

Quote:

I'm proposing larger optical tables at the ends to avoid the existing overcrowding. This would allow the initial pointing and optical level beams to set up correctly.

The existing table is 4 x 2 would be replaced by 4' x 3'   We would lose only ~3" space  toward exist door.

I'm working on the new ACRYLIC TABLE COVER for each end that will cost around $4k ea.  The new cover should fit the larger table.

Let me know what you think.

I'm not sure I see the motivation.  The tables are a little tight, but not that much.  If the issue is the incidence angle of the IP and OPLEV beams, then can't we solve that just by moving the table closer to the viewport?

The overcrowding alone doesn't seem bad enough to justify replacing the tables.

Steve pointed out to me (this is not in his original elog, although you can see it in the photo if you look closely), that we can't really move the table legs any closer to the chamber.  We have maybe 3" of clearance between the table leg and the blue support tube that supports the bottom of the stack.  Therefore, we can't just

So Steve's proposal is to leave the legs exactly where they are, and just put a larger table on those legs.  This leaves 9" unsupported on the chamber side, and 3" unsupported on the far side.  The tables are 4" thick. 

Steve also mentions that we will lose 1.5" on all 4 sides of the table, with the new acrylic boxes, so we'll be down to 1'9" unless we get the larger table, in which case we'd have 2'9", and 3'9" on the long direction.

I would like to see a sketch of the end tables, so we can see if 1'9" x 3'9" is enough.  Manasa is working on a new end table layout in parallel to the ringdown stuff.  If we're actually concerned about the input angle of the oplevs, then to fix that we need to either get the bigger table and hang it off the edge of the legs, or perhaps as Dmass suggested, get a "doggy cone collar", and give ourselves a larger opening angle of access to the viewport, from the current table location.

 

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