40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log  Not logged in ELOG logo
Entry  Thu Mar 10 16:29:32 2016, gautam, Update, endtable upgrade, Inventory check Inventory_check.pdfDoubler_comparison.pdf
    Reply  Thu Mar 10 16:32:45 2016, rana, Update, endtable upgrade, Inventory check 
       Reply  Mon Mar 14 22:42:23 2016, gautam, Update, endtable upgrade, Inventory check 
       Reply  Mon Mar 28 10:43:18 2016, Steve, Update, endtable upgrade, ETMX 4'x2' optical table pictures ETMX4x2Layout.jpgETMX_4x2.JPGETMXopt_4x2.JPG
          Reply  Wed Mar 30 17:38:52 2016, gautam, Update, endtable upgrade, X end table proposed layout  ETMX_3x2.JPGlayout_details_20160328.pdfETMX_proposed_layout.pdf
             Reply  Thu Mar 31 09:38:41 2016, Steve, Update, endtable upgrade, Y end 4x3 existing layout ETMY4x3layout.jpg
                Reply  Thu Mar 31 19:49:31 2016, gautam, Update, endtable upgrade, proposed layout v2 ETMX_proposed_layout_v2.pdf
                   Reply  Mon Apr 4 10:59:12 2016, gautam, Update, endtable upgrade, proposed layout v3 ETMX_proposed_layout_v3.pdfIR_modematch.pdfGreen_modematch.pdfXendALaMode.zipETMX_proposed_layout_dimensions.dwg
                      Reply  Mon Apr 4 15:04:14 2016, gautam, Update, endtable upgrade, COMPONENT REMOVAL 
                         Reply  Tue Apr 5 11:42:17 2016, gaericqutam, Update, endtable upgrade, TABLE REMOVAL 
                            Reply  Wed Apr 6 17:52:21 2016, gautam, Update, endtable upgrade, First contact cleaning commenced 
                               Reply  Thu Apr 7 12:51:24 2016, gautam, Update, endtable upgrade, Beam height differences 
                                  Reply  Thu Apr 7 14:30:58 2016, Steve, Update, endtable upgrade, ETMX table height ETMXbrs.pngETMX.jpgIMG_0618.JPGETMX.jpgETMXwc.jpg
                                     Reply  Fri Apr 8 09:13:20 2016, Steve, Update, endtable upgrade, ETMX-T beam height ETMXalignedT.pngETMXF.jpg
Message ID: 12060     Entry time: Mon Apr 4 10:59:12 2016     In reply to: 12058     Reply to this: 12061
Author: gautam 
Type: Update 
Category: endtable upgrade 
Subject: proposed layout v3 

I realized I had overlooked an important constraint in the layout, which is that the enclosure will have two supports that occupy some region of the table - these are denoted in blue in v3 of the layout (Attachment #1). I measured the dimensions for these from the existing Y-endtable. The main subsystem this has affected is the IR transmission monitors, but I've been able to move the photodiodes a little to accommodate this constraint.

I've also done the mode-matching calculations explicitly for the proposed new layout (Attachments #2 and #3, code in Attachment #4). While the layout was largely adopted from what Andres posted in this elog, I found that some of the parameters he used in his a la mode code were probably incorrect (e.g. distance between the 750mm lens and the ETM). More critically, I think the Gouy phase for the optimized solution in the same elog is more like 60 degrees. I found that I could get a (calculated) Gouy phase difference between the two PZT mirrors of ~81 degrees by changing the green path slightly, and making the two PZT mirrors Y7 and Y8 (instead of Y7 and Y11, for which the Gouy phase difference is more like 50 degrees). But this way the two steering mirrors are much closer to each other than they were before. Other misc. remarks about the mode matching calculations:

  • The beam diameter at the locations where the Faraday isolators should go is well below 5mm, the aperture size of the Faraday isolators
  • The calculated mode-matching efficiencies suggest that we don't need any cylindrical lenses though the mode from the NPRO is elliptical
  • Attachment #5 is a CAD drawing of the layout with all dimensions used for the mode-matching calculations included (although they are in inches)

These changes also necessitated minor changes to the transmitted IR beampath and the Oplev system, but these changes are minor. I've also switched the positions of the AUX IR power monitoring PD and the fiber coupler as suggested by Koji. The shutter has also been included. 

Attachment 1: ETMX_proposed_layout_v3.pdf  290 kB  | Hide | Hide all
ETMX_proposed_layout_v3.pdf
Attachment 2: IR_modematch.pdf  100 kB  | Hide | Hide all
IR_modematch.pdf
Attachment 3: Green_modematch.pdf  119 kB  | Hide | Hide all
Green_modematch.pdf
Attachment 4: XendALaMode.zip  3 kB
Attachment 5: ETMX_proposed_layout_dimensions.dwg  1.125 MB
ELOG V3.1.3-